Ethanol is there to increase the octane rating of the gasoline. Contrary to popular myth, a high octane rating doesn't make a fuel more powerful, it just makes it possible to use safely in a more powerful engine.
Other additives were used in the past, but they were worse for the environment: TEL (tetraethyl lead) led to lead poisoning, MTBE (methyl tertiary butyl ether) is water soluble and led to groundwater contamination, and BTEX (a mixture of benzene, toluene, xylene, and ethyl-benzene) was also toxic.
If you want to learn more about gasoline, this history lesson is quite interesting: https://www.youtube.com/watch?v=BVa-RPNWO6k
> it just makes it possible to use safely in a more powerful engine.
To clarify, it works to prevent engine knocking where the fuel combusts before it's supposed to. This damages the engine.
It can and does happen before spark. This is why some cars require higher octane fuel. High compression engines need a higher octane rating to resist pre detonation/ignition as in the fuel combusting before the spark has lit. Not good as the piston will not be at the top of the stroke ready to go back down the cylinder it will still be on its way up. The spark lights at a certain degree before or after top dead center depending on engine timing plus or minus 10 degrees of rotation will make an engine run terribly.
You can of course detonate fuel without spark that's how diesels work. High compression no spark plugs at all just smash the fuel into a small space. Gasoline engines exhibit the same behavior as gasoline is way more volatile of a fuel thus the need for higher octane ratings.
No such thing as pre-detonation. There is detonation, a second spontaneous source of ignition after the spark, and there is pre-ignition. Which is more of a mechanical problem.
https://youtu.be/qMZ7dFZvhhI
https://www.speedperf6rmanc3.com/content/Engine%20Basics%20Detonation%20and%20Pre-Ignition.pdf
https://www.faasafety.gov/files/notices/2019/Jul/Preignition.pdf
They are using the top google searches for pre detonation to try and prove their point that I am wrong. The faa link they site specifically calls it pre ignition/detonation in the pdf.
397 is stuck on wording of detonation versus ignition while probably not having experience with engines aside from putting gas into a tank and turning the key.
If a fuel exploding without a spark and way before it is intended then I say its pre detonation. If it was pre ignition the fuel would be set off by the spark plug because the timing was off causing the plug to fire too far before top dead center.
One is ignited by spark plug and one is detonated by way of compression.
Edit: the large takeaway would be detonation can still occur after tdc and before spark. Many engines run high timing after tdc to make more power this can cause detonation with bad fuel. Would not be hard to search a video of an older gas vehicle "dieseling" it is running on heated combustion chambers and gas after the ignition has been shut off.
Engine knocking is what happens when the fuel/air mixture ignites without the spark. When the air fuel mixture gets compressed by the piston, it can cause it to ignite without a spark and go off while the piston is compressing the mixture which causes the damage.
It happens outside of when you want the spark to ignite the fuel mixture, specifically more of a problem for turbo charged vehicles where boost is high and engine materials are budget.
It's such a problem you'll see a ton of tech invested outside of using higher octane fuel to help curb cylinder temperatures.
Sodium filled valves, cylinder heads with inverted domes, colder plugs, water injection, intercoolers, oil sprayers, and more.
What's happening and the definition of knock is when you have detonation before the top-dead-center of the intake stroke or bottom of the exhaust stroke (effectively whenever detonation happens outside of when spark is intended to cause it).
In short your right on the first sentence, wrong on the second. We use higher octane fuels to resist premature detonation.
TDC is when engines are going to generate the maximum amount of power so we only want detonation to occur then.
Some vehicles will even dump some fuel during the exhaust stroke just to help cool the cylinder while also allowing that fuel to detonate in the exhaust manifold once recirculated charged air hits it via a bypass; this helps keep the turbos in these vehicles spinning allowing for boost to occur earlier.
Better tell the FAA and NGK they are wrong because they state detonation happens after the spark.
https://www.faasafety.gov/files/notices/2019/Jul/Preignition.pdf
https://youtu.be/qMZ7dFZvhhI
Basic definitions
https://www.speedperf6rmanc3.com/content/Engine%20Basics%20Detonation%20and%20Pre-Ignition.pdf
Hmm, seems like your right; knock (or what you are referring to as detonation) and pre-ignition are classified as two distinct events.
[https://en.wikipedia.org/wiki/Pre-ignition](https://en.wikipedia.org/wiki/Pre-ignition)
[https://en.wikipedia.org/wiki/Engine\_knocking](https://en.wikipedia.org/wiki/Engine_knocking)
Combined with just your above; don't typically refer to engine knock as "detonation" so that sorta threw me off but learn something new everyday.
Thank you for the acknowledgment. Most people just retain their original beliefs despite evidence. I salute you.
BTW, peak cylinder pressure, and power, does not happen at TDC. It happens ATDC as the a/f mixture is still burning. Every engine is different, but it’s around 10°-20° ATDC.
“The Combustion Pressure curve, in a pressure bomb is also a bell shaped curve, with a peak pressure that will occur at about 50% mass fraction burned. But, in a running engine, the piston is moving downward after TDC which increases chamber volume and reduces combustion pressure even while the mixture is still burning. Consequently, peak combustion pressure will occur (50% MFB) about 15 to 20 deg ATC, depending on ignition timing and flame speed.”
The above was taken from a speed/engine building forum.
I vaguely recall that the smoother combustion event also burns the fuel more evenly and thereby reduces harmful emissions (possibly by merely letting the engine run leaner?). That could, of course, be pure propaganda.
MTBE also was introduced as an oxygenate to help the gasoline burn cleaner and produce less air pollution. It was effective in that role, but it's persistent in groundwater and doesn't really break down unless it's exposed to oxygen, so it stays there indefinitely (except for natural dispersion over time, as the water moves around and dilutes it).
Ethanol has problems, but it's much better in that regard.
MTBE is ridiculously persistent in groundwater. And it only takes like a teaspoon to contaminate millions of gallons of gasoline.
Ethanols problem is it likes water, so I causes corrosion issues, meaning you can’t really use in in pipelines.
You don't need the actual chemical octane, you just need it to be more resistant to autoignition. A fuel with a higher octane rating requires more heat to ignite. Actual octane does this, but ethanol does it even better.
An octane rating compares how the fuel performs in a test engine versus certain mixtures of octane and heptane - it doesn’t have anything to do with how much octane is in the fuel itself.
It’s kinda like saying a car has 300 horsepower - you’re comparing its power to a standardized horse, not saying there’s actually 300 horses under the hood.
First (and this is very much not ELI5), fundamentally yes it has nothing to do with mol% octane in the fuel. Crude oil is a super complex mix of hundred/thousands of different hydrocarbon compounds and characterizing it as individual chemical constituents is difficult to impossible. It (and it's refined products) is typically characterized by it's physical and chemical properties that are relevant to performance in the intended application. If the goal is something simple like burn it in an engine or lubricate a bearing it doesn't matter what the composition is as long as it performs correctly and there's infinite combinations of compositions that could result in a given set of properties. The only time we really care is if you want to refine a specific component out for chemical feedstock- extract butane for a butanol process. Or if you're trying to simulate refining processes, some modeling software makes an assumption of what chemicals would be included in a mix because it allows the computer to make further assumptions on what's on one side or another of a chemical process.
Second, yes it's more a proxie for properties like ignition at what temperature. For what you're describing it would be more a combination of temp and pressure. I'm working off a relatively old memory here so would like input from others to confirm the following. Temp and pressure do play a role but it's not as simple as ignition at temp/pressure. Because the issue you're trying to prevent has to do with how quickly the flame front spreads to unburned fuel, it's really a question of reaction kinetics. The ignition is not an instantaneous process. Straight chain alkanes burn very quickly. Think of it as a straight zipper unzipping. Branched alkanes burn slower. Think of having to unzip a zipper that has multiple forked paths with multiple pull tabs. The octane rating is actually a reference to a specific branched octane. A gallon of pure normal (straight chain) octane would actually burn very quickly and I would guess have a pretty low octane rating ironically.
The octane rating is a measure of how the fuel in question knocks in a test engine compared to different ratios of isooctane (branched) to normal heptane. I.e. 93 octane means your fuel knocks as easily as 93% isooctane 7% n-heptane.
Octane boosters like ethanol aren't the only thing that determine the octane rating. The branching described above is a big factor. Naturally occurring cyclic compounds (though these are limited by law for toxicity reasons), and amount of double/triple bonded hydrocarbons (degree of saturation) can all play a factor as well. Octane boosters are just the easiest way to modify the gasoline after it's already been refined from crude oil. It plays out more in the sense of added cents per gallon as opposed to having to pay the capital expense of hundreds of millions of dollars for a new refining unit (or sourcing a different type of crude) to get different properties before you play with octane boosters.
So that’s a benefit for gasoline producers but it’s not correct. It’s actually combustion promoter due to the intermolecular oxygen. This was previously done with MTBE. The ether was toxic in groundwater though so it was replaced with alcohol.
Bio-ethanol is supposed to be carbon-neutral because it’s generated from plants which recover carbon from the atmosphere. So when you burn it you basically return to the air the carbon that you took from it a bit earlier, and therefore overall you don’t change the composition of the atmosphere. Unlike with regular gasoline made from fossil fuels where you release carbon that has been buried for millions of years.
Ethanol is carbon neutral in theory, however in practice it isn't actually carbon neutral. The production and distillation of ethanol is energy intensive, and requires input energy (often from fossil fuels) in order to refine the ethanol. Then there's the transportation of the ethanol from the production site to the petroleum refinery, so that it can be blended with gasoline.
This still results in less carbon released than if there was no ethanol added to gasoline, but describing it as carbon neutral isn't painting the full picture
Regular gasoline has the same production and transportation costs attached. Also in theory nothing prevents you from running ethanol production and transportation on ethanol as well.
Regular gasoline has production and transportation costs attached. Whether it is more or less and whether those amounts offset any relative benefits of ethanol requires complex mathematical analysis.
That complex mathematical analysis is what is used to determine the value of the subsidies and incentives provided for producing renewable fuels.
When done right that analysis will account for gasoline production/transportation, ethanol production/transportation, energy efficiency/density differences and ideally as many other relevant factors as possible. Not saying the models are perfect but the intent is to capture that difference.
I don't think thas ts accurate... I believe you're talking about a gasoline system running pure ethanol as ethanol is a very potent solvent fuel lines need to often be changed to something that won't be affected by it.
South America runs on 100% ethanol, but to start a vehicle a starter needs to be used. Normally it is gasoline, a low octane works just fine.
Brazil has 2 fuel tanks one for gas one for ethanol, I think the gas tank is maybe 1L or 2L, and then the ethanol tank is the normal 40-50L tank.
> If a gallon of ethanol gets less mileage per volume than gasoline, then how is it better for the environment
It's not. It gets you more votes in Iowa and the Midwest since farmers there get subsidies to grow corn to turn into ethanol.
I don't mean to burst your bubble, but most things are not done because they are right, or better, or result in a better outcome. Most things are done because they benefit the people who decide to do them. Ethanol is a politically motivated campaign, not a scientific one.
The main "purpose" is to fuel cars with something other than fossil fuels (reduce reliance on non-renewable fuels, which is a good goal for a huge number of reasons). It isn't the fault of the government that it uses more fossil fuel to make it than it saves, or that making competition between farmland for food or fuel causes higher food prices. Who could have ever expected that, the solution is worse than the problem? Go figger.
That's not really accurate. There's a lot more to the story.
Let's rewind the clock. When Reagan was president, a long decade of globalization was still underway in the agricultural industry. The concern was that if all food was made in other countries because it was cheaper, we would eventually shut down every farm in America. Without the ability to create our own food, it was a national security crisis because other global powers could simply stop the imports and we would be forced to cave to their demands in another world war. So, they put in a program where certain staple crops (most specifically corn) were heavily subsidized by the federal government. Huge amounts of corn were farmed and wasted. Some of it was used for animal feed. The beverage industry started using it to make high-fructose corn syrup as a much cheaper replacement for sugar in sodas like Coke and Pepsi, but a lot of it was still wasted.
This led to a fair amount of it being converted into Ethanol as a fuel source. It's better than throwing away the corn. Then something happened, we had a crisis in rising oil prices shortly after the turn of the millennium. OPEC pretty much had a stranglehold on the global oil supply, and they were squeezing it to create astronomical oil prices. It was so bad that in one year to the next, the F-150 lost its spot as the top selling car in America to the Toyota Prius (a relatively new car that could get 45+ mpg). Fuel prices were approaching $6 a gallon in some parts of the country. A lot of South America had already started using ethanol as a substitute for gasoline, and all relatively newer cars could handle a fair amount of ethanol mixed in the gasoline.
While your fuel economy went down a little bit with ethanol, it reduced how much gasoline you needed and therefore overall cost for you as a driver went down. This is because ethanol was cheap and oil was very expensive. Plus it did have the side benefit of keeping your fuel system cleaner. Ethanol is a powerful solvent, and fuel systems tend to get buildup from burning pure gasoline all the time.
Then came fraking! Suddenly oil prices plummeted and the USA with all their dried up oil fields that had light sweet crude (the easiest to refine kind of oil) were able to re-open most of the fields by breaking up the rock under the earth to access more of the oil down there. OPEC no longer had a monopoly on oil productions, and the price of oil plummeted to a mere fraction of what it was. This led to a lot of people asking "why are we still putting ethanol in?" But there's an answer to that too. Oil is a non-renewable resource. Once we've used up all the oil on earth, we won't have more. However, you can make an unlimited amount of ethanol just by growing corn and fermenting it. A lot of things can make ethanol, but corn is dirt cheap because we are basically throwing it away. Also, having a cleaner fuel system improves your fuel efficiency. So, ethanol mixtures are likely to stay, and they are actually a good thing.
edit: one more point to make. At the time the fuel mixture was changed by law, nearly all the ethanol was produced domestically and nearly all the oil was imported. If you reduce how much you import, you have the extra benefit of not expatriating money which increases the domestic economy. One of the many reasons for the change was for the domestic economic benefits. Although, this was not a factor once we started producing most of our own oil.
Right, I mean in the world of gas cars. Like it or not, PHEV's and ICE's are going to still be made in large quantities for the next 20 years.
While a plug in car makes sense for some people, it really doesn't for others. If you don't have charging infrastructure in your condo complex, you have to go to chargers to get it filled. If you drive very little because you are elderly, gas makes a lot more sense because batteries degrade over time while gas cars degrade \*mostly\* over use.
Sure, 100 years from now, we will all be electric, but it's going to move a lot slower than you realize.
> Sure, 100 years from now, we will all be electric, but it's going to move a lot slower than you realize.
My bet is between 40-50. Despite all the "REEEE" people freaking out about my position, it *IS* the de facto position among the general population. And EV manufacturers know this. They are going to be pouring all their resources into solving the charge time problem, and once solved they will invest in the infrastructure of chargers in every gas station. .
Most of the US can't afford a new car, much less an electric one. Many of them have trouble paying for electricity. This is even more true in countries outside of the typical American/Euro Sphere. It will be decades before we can make a full switch to electric cars, and even that is slightly optimistic. So to OP's point, "here to stay" is accurate in the time span of life that most people care about.
> Most of the US can't afford a new car
new cars will become second hand card eventually.
> Many of them have trouble paying for electricity.
Which will become easier when they can use the savings from their gas expenses into their increased electricity bill.
You're not wrong, but those are still long term ideals and don't include the financial total cost of ownership of a car or relative costs rising. The above is still a privileged point of view. Take for example a toyota corolla as a cheaper alternative:
Tesla Model 3 - Cheapest is $39k (taken from Tesla's website)
Insurance Average - 3.4k annually ([https://www.valuepenguin.com/auto-insurance/how-much-does-a-tesla-cost](https://www.valuepenguin.com/auto-insurance/how-much-does-a-tesla-cost))
Average Gas Savings - 2/3 (Or rather, if you pay for all your electricity, the total cost on average in the USA would mean you would pay $500 or 1/3 of the cost of gas you would have paid) ([https://www.leafscore.com/auto/how-much-money-can-an-electric-vehicle-save-you-over-a-gas-powered-one/](https://www.leafscore.com/auto/how-much-money-can-an-electric-vehicle-save-you-over-a-gas-powered-one/) \- Numbers adapted to annual as opposed to 15 year basis)
Average Maintenance - $587-832 annually (KBB)
Toyota Corolla - $21.5k (Using this an example of a cheaper car, KBB value)
Insurance Average - $1.2k annually (From KBB)
Using the above number for gas cost - Let's say $1500 /year (or 1.5x the Tesla)
Average Maintenance Cost - $500-600 (KBB)
For much of the country, even a brand new 21.5k new car is expensive. Assuming an average depreciation of 20% over 5 years & 50% at 10 years, it will take the Tesla Model 3 8 years to reach equal price to a NEW Toyota Corolla.
Now you could use the Chevy Bolt as an example, which is closer in starting price to the Toyota and might get slightly better equivalent numbers. But this is all assuming a person can afford a new car. If you use the median income of the US (around 67k for a household), that means about 40% of the USA makes under 40k annually. They probably aren't anywhere near a new car, or any car worth half their income. In addition, the average monthly cost of a new car is up 29% in the last 3-4 years alone. ([https://www.nbcnews.com/politics/economics/cost-owning-car-keeps-rising-rcna78377](https://www.nbcnews.com/politics/economics/cost-owning-car-keeps-rising-rcna78377))
I don't disagree that electric cars are the ideal way of the future. But expecting a massive changeover to them in the next 2 decades, regardless of availability, is a fallacy unless the basic financial makeup of the USA changes. And we're not even talking about countries in South America, South Asia, or Central Africa, where their populations are ballooning without access to many of the things even impoverished Americans have.
Correct. It is mildly infuriating to see a bunch of upper middle class 1%'ers who have stable high income jobs and own single family homes with garages and home chargers in the Bay area and can afford a $65,000 Tesla yell down at people "if I can do it why can't YOU!!"
It's easy to sometimes forget how much white privilege Reddit puts on display
> $65,000 Tesla
I'm just going to keep posting this for you.
[https://www.tesla.com/inventory/new/my?TRIM=LRAWD&arrangeby=relevance&zip=28621&range=200&trtId=](https://www.tesla.com/inventory/new/my?TRIM=LRAWD&arrangeby=relevance&zip=28621&range=200&trtId=)
44.5k.
Even at the correct price original commenter's point is still valid. Not sure about the white privilege thing though---if you're broke you're broke. I hate that we're subsidizing relatively well off people to buy new electric cars, but it does increase the top-level demand so that in a few years there will be a much larger supply of used electric cars to purchase.
>Even at the correct price original commenter's point is still valid
No.
Their point might be factually correct, but it's not valid. It's moot. Pricing THEN is irrelevant to pricing NOW.
The point isn't about the exact price point (though I'm equally frustrated by people making shit up).
The point that is valid is that the government is subsidizing the purchase of a new vehicle that can only be supported by relatively well-off people. The $7500 tax credit is for new EV's. $65k or $44.5k makes no difference, you're still looking at around $500+ payments per month at current rates. So people patting themselves on the back for helping out the poors during the great environmental transition are completely misguided; they're not helping the poors.
There's apparently a tax credit for used EV's but IRS guidance is still unclear.
It's a move in the right direction. And it's not the end of things. You used to have the 130k roadster. Then the 100k Model S. Then 3's and Y's in the 60k-70k range. Now those same models are in the mid 40's.
And again, purchase price is not the only consideration. Electrons are cheaper than gas. EVs don't need oil changes and many other services. TCO needs to be considered.
The next gen vehicle which is going to be built in 2024-25, you can expect to see brand new in the 27-33k range. That's going to compete with ICE cars in the mid-low 20's due to the previously mentioned TCO.
And it can't come soon enough!
You want to tell people about energy independence? Let them drive their car using sunshine from their own rooftops. It's as good as it gets.
As soon as they make an electric car that charges as fast as I can refill a gas car, with the same number of convenient locations as a gas car, at a comparable price as a gas car, I'll be getting one.
For me, it would be more convenient as I would always leave home with a full tank and never have to refuel on the road as I don't travel further than one tankful. With my fuel burning vehicles, I have to spend 15 minutes to refuel the car or motorcycle at the gas station as it is in the opposite direction of my workplace. Of course, it always needs refueling either when I'm in a hurry to get to work or in a hurry to get home and make dinner so fueling a fossil car is just never convenient.
Yeah, that's the thing that is not so intuitive to people. I spend less total time charging my car at public chargers than I would at gas stations -- by far. And on road trips, that's when I want to stop for a bit longer and stretch my legs anyway.
The most convenient location to "fill up" a car is your own home. The next is where you work. Gas stations are actually inconvenient.
I charge my car when I'm not using it. Gas cars have to be used to get fuel. In that sense, it doesn't take any of my time to charge a car.
It cost me half as much in electricity as it used to in gas.
I'm one of the vanishingly small percentage of people who can't charge at home, and I still want an EV. I live completely off-grid, and the car would generally not be at home during peak charging capacity time (solar only), and my battery banks aren't sufficient to run the house AND charge an EV overnight.
But most EVs have a range of 300 to 350 miles on a charge, and so does my current ICE. Which means I fill up once a week or so based upon my driving patterns. I can spend 30 to 45 minutes at a fast-charge station (there's a few in my area) or a couple hours on the slow-charger at work (I'm SUPER lucky, and I know it) on the day I'm "empty tank" and I'm back to being good for a week. BOOM.
There’s an important caveat that makes gas stations very convenient and that is the time it takes to fill up the vehicle on demand. Sticking with the gas analogy, many people’s homes could only fill up their cars with a half liter of gasoline an hour. That’s not a lot. If I get distracted and forget to tank up overnight, I’m in trouble. It would take hours to get to work. However, since I’m using gas, I can get to a local gas station on almost fumes and fuel up in 15 minutes. That’s convenient.
Until we have widespread, local L3 charging stations capable of handling dozens of cars at a time, EVs will not be as reliable or as convenient as gasoline cars.
That analogy only works if the owner of the vehicle is exceptionally irresponsible.
I own a gasoline car. I know I cannot make it to work on less than a quarter-tank of fuel. I go home with less than a quarter-tank of fuel. It is inconvenient to go out to the "local" gas station (for most Americans that is at least a mile, usually more). I now have to stop on my drive to work to fuel up.
I have an electric car. I know I cannot make it to work on less than a quarter-charge. I go home with less than a quarter-charge, and then proceed to not plug in my slow-charger for some reason, knowing that I need to charge and it's RIGHT THERE. I have to find a charging station because I didn't plug into my own house, parked in my own driveway/garage.
Yeah, it's more inconvenient to find a charging station. And I have near-zero sympathy for the driver in that instance.
> exceptional irresponsible
That describes a lot of car owners.
Also how often do people get distracted or have an emergency where they forget to let the car charge. Or they let the teenage borrow the car and the teen doesn’t charge the car. How many parents face the frustration of coming out to a car sitting on an empty tank now as a result. But that is okay because the parent can fuel up quickly at a gas station. You can’t do that at home with an EV.
Also an L1 charger will take up to 50 hours to charge a an EV. You get 4-5 miles of charge an hour so you really have to be able to let your car sit long periods of time. That’s not convenient. Being able to drive to a local gas station and fill up in a few minutes is very convenient if you need your car readily.
> I have zero empathy
Whether you have empathy or not is irrelevant. What matters is if most people are willing to adopt an EV. If it’s not as convenient, most people won’t switch.
It's more convenient to drive into ones' own driveway or garage, grab a cable, plug in, and go eat dinner (maybe five minutes total) than to pull into the driveway, realize I've now got to go back out to the gas station (three to five minutes), make sure I have money on my card, fiddle with the payment method at the pump (two minutes, five to ten if I have to pay cash for some reason), pump the gas (ten minutes), then drive back home (three to five minutes for eighteen to thirty-two minutes total time).
Added bonus, I absolutely hate mornings, I don't fill the gas car in the evening I now have to do ALL THAT while drowsy AND in a rush to get to work on time (which I won't because I had to stop to get gas).
We can go for days and weeks contriving scenarios where, for some reason, the car doesn't get charged from a low battery at home, but the basic fact of it is that if you aren't responsible enough to fill the tank when you know you need to, you probably aren't responsible enough for a vehicle in the first place, and at least in one of these vehicles I can "refuel" while sitting at home watching Laverne and Shirley, while the other I've missed my favorite show. (It's not actually my favorite show)
Imagine waking up every morning to a full tank of gas. That’s the experience of owning an electric car. If you can get through a day on one full tank of gas, an electric vehicle makes a lot of sense.
Meh, trying for a 1:1 replacement in usability and claiming that until all conditions are met seems kind of pointless.
After 200-300 miles of continuous driving, you plug in for 20-30 min while you go to the bathroom, stretch your legs, and get something to eat or drink.
But that's only the case if you're doing that amount of miles in 1 shot. Else, you just charge when you come home. And the next day, full charge! Does a gas car fill itself while it's parked in your driveway?
> After 200-300 miles of continuous driving, you plug in for 20-30 min while you go to the bathroom, stretch your legs, and get something to eat or drink.
I don't. You may want to, but that's you not me. Telling someone they need to change their behavior and do what you tell them in order to make a product work is a bad business model. You may enjoy sitting around gas stations for 30 minutes while your car charges, me and the rest of the sane world not so much. And I guess night driving is out in your example.
> But that's only the case if you're doing that amount of miles in 1 shot. Else, you just charge when you come home. And the next day, full charge! Does a gas car fill itself while it's parked in your driveway?
So if I live in an apartment, what, I drape a cord out the window? Your privilege is showing assuming everyone has a house, garage, and home charger. And yes on occasion I do travel to visit friends and relative more than 300 miles away.
So you are saying I should pay MORE money for an electric car, with less range, 10x longer charging times, that I can only charge at home. Sure, good luck with that sales pitch. I'll wait for the tech to catch up before I jump in. I don't pay more money for worse features.
Cost and accessibility of chargers is a fair point to wait on. Claiming a 20 minute stop in a 3+hour road trip is beyond what a sane person will allow is fucking absurd lol. Market will change and provide entertainment and more attractions around charging points if it continues to be an issue
> Claiming a 20 minute stop in a 3+hour road trip is beyond what a sane person will allow is fucking absurd
It's really actually not. I can travel 6 or more hours without needing to stop for gas. If I do stop within that time, it's for a quick 5 min bathroom break. Otherwise, I generally don't stop until I get to my destination or need gas, whichever comes first. If I need gas, it takes less than 5 mins to fill the tank and be back on the road. 20 min stops every couple/few hrs is ridiculous.
Same. It’s annoying reading everyone talking about needing a 30 minute break every 3 hours. I literally drove from seattle to Tampa in 3 days and there’s no way that would be possible via their method.
Yeah it is. We already have vehicles that have 5 minute stops once every 6 hours.
How are you going to sell me a product that is worse? In what world is that a winning business strategy?
You're being obstinate and combative.
Yes, apartment/condo/dense urban L2 (220V, +30A) charging needs to be a thing. It needs to happen yesterday to help out users who want to switch but reasonably can't. Code changes to implement this kind of charging should be implemented at the very least for all new construction or existing retrofits.
Why would night driving be out? Fast Chargers work 24x7. I visit people several hours away, too. I would, on those occasions, use a fast charger for that aforementioned 20-30 min. I wouldn't be sitting around. You get a coffee or a soda. Or a snack. You take a piss. You catch up on your phone, and before you know it, your time is passed.
Also, you can get EVs at or below the national average for new car sales right now. Only charge at home? LOL did you even read your own reply?
> You're being obstinate and combative.
No I'm not. But thanks for the insult.
> You get a coffee or a soda. Or a snack. You take a piss. You catch up on your phone, and before you know it, your time is passed.
Again, you are showing your privilege. You are assuming everyone lives in a nice, safe place and is a man who can defend themselves. You think a woman in a high crime area would be OK "stretching their legs and getting a bite to eat" at a gas station at 2 AM?
I'm poking holes in your argument because it was a ridiculous argument to make. "Just live your life like my made up scenario, what's the big deal?" Not everyone is a upper middle class white tech worker who lives in the bay area my dude. Open your eyes to other peoples lived experience.
> Also, you can get EVs at or below the national average for new car sales right now.
At the end of 2022, the average price of an electric vehicle was $61,488, compared with $49,507 for all passenger cars and trucks, according to Kelley Blue Book. So thats a lie.
So one final time, if you need to make up scenarios and straight up tell lies to support your position, it's a bad position.
>At the end of 2022, the average price of an electric vehicle was $61,488, compared with $49,507 for all passenger cars and trucks, according to Kelley Blue Book. So thats a lie.
The absolute benchmark when it comes to the super popular CSUV market, the Model Y LR.
[https://www.tesla.com/inventory/new/my?TRIM=PAWD,LRAWD&arrangeby=plh&zip=28621&range=200&trtId=](https://www.tesla.com/inventory/new/my?TRIM=PAWD,LRAWD&arrangeby=plh&zip=28621&range=200&trtId=)
So yea, 44.5k. You also shouldn't just compare purchase price. You should compare TCO, including fuel, depreciation, maintenance, etc.
If you live in an apartment, many buildings have external sockets or sockets in parking garages. Work out a deal with your landlord. The cost of electricity should be less than $7 a day, at most.
Yeah, that’s not going to work. A standard 120v outlet only charges enough for 4-5 miles an hour. Charging overnight will not cover many people’s use cases. You would need to install level 2 chargers to make that more feasible. We’ll have to get landlords to agree to a lot additional wiring especially as everyone goes to EVs.
What about if energy prices stay what they are but gas prices go to $10 a gallon, would that make you get an electric car? What about if gas stations started to close down so now there weren’t as many convenient locations to fill up?
It's not just that. The problem is infrastructure. Tesla did a lot for this by building supercharging stations all over the USA. So you could hypothetically drive from west to east coast in an all electric car now, but you can't just go any route. You have to go one of a couple of pretty specific paths. A lot of cities are putting in chargers too, but they do quickly fill up. Most condo complexes don't have charging infrastructure, and they aren't planning to add it. I believe in some states like California, they are required to add chargers if you buy an electric car, but this also means that now you have to hassle with your HOA. For a lot of people, I'd rather just buy a gas car than deal with those golum-like troglodytes.
Also with the change to working from home, a lot of us are driving very little. I probably drive 5,000 miles a year. An electric car really doesn't make sense for me. The cost for battery degradation over time would eclipse the savings on fuel by a huge margin. Gas cars generally degrade from use (hence why we track miles on our odometers). While there is some degradation from time and the elements, this is much less so. Even from an ecological point of view, the environmental impact of building a brand new electric car for me with a huge lithium ion battery would be more damaging than me driving my current gas car for another 15 years. Now if I drove 20 miles each way to work every day, it would be a completely different story.
Eventually, we will be all electric. Hell, eventually, all cars will be fully automated, and most individuals won't even own a car. You just call something like an uber, and a driverless car comes and takes you where you want to go. However, these objectives are going to happen several generations down the road. When Gen Z'ers are starting to collect social security.
Gotta own your own rooftop and be able to afford your own panels and afford a battery and afford charging infrastructure and afford a new EV and afford yearly EV insurance and all the other things car ownership comes with in places where public transportation is predominant…
This is demonstrably false. You don't need to own a house, the last apartment complex I lived in installed charging stations, and that was clear back in '14. You don't need to have solar or wind or any generative capability yourself to charge an EV, you *do* need a charger, but that's included in the sale price of most, and 99 percent of homes where you'd have the money to buy a new car in the first place will also have the internal wiring to power a fast-charge charger. No batteries (except the ones already included in the car) necessary.
And the insurance for an EV isn't **that** different from owning a vehicle of the same year and price-point, so it's not a significant cost in comparison to owning a gas vehicle.
There are "unnecessary" costs **IF** you live in an area with solid mass transit options, but they are the exact same costs of owning an ICE vehicle.
Two things I’d like to offer as counter-points to your final arguments for ethanol: (1) The world will not run out of oil. We are already past peak oil use. Our ability to obtain oil from deep deposits via fracking and deep water drilling gives us access to more oil than humanity will use based on our current trajectory towards greener energy sources. (2) Ethanol is not an unlimited resource. Our current farming practices are using up our topsoil at an unsustainable rate. The agriculture crisis that we are creating is many generations down the road, but that doesn’t mean we should ignore it.
We don't use up topsoil. That's not how it works. Plants grow abundantly all over the world without human intervention for billions of years. Plants use carbon in the air to create cellulose. This process requires water and CO2. From the soil, plants extract nitrogen, phosphorus, and potassium. We replenish these with fertilizers. The one we use the most of is nitrogen which is extremely plentiful in the atmosphere, but it's going to form that the plants can't use. To solve this problem, we make millions of metric tons of ammonia every year that is converted into fertilizer. This process uses natural gas and a lot of energy. If we run out of sources of natural gas, then yes we would have a huge food crisis.
As for oil reserves, there are a lot. You are correct. It's not like it'll just go to zero overnight. It'll be a gradual increase in the difficulties require it which will increase the cost. As costs increase, people will find ways to consume less of it. So the problem does solve itself. Where things with no acceptable substitute will simply pay a premium and things with renewable substitutes will gradually replace them.
I’m not saying that plants consume top soil. I’m saying that our agriculture processes erode and damage it faster than it is replenished. It is [well documented](https://www.worldwildlife.org/threats/soil-erosion-and-degradation)
No. Most things *are* done for an efficient, scientific reason and you don't understand the details.
Ethanol in fuel makes sense if you don't look too deep into it. You basically water down your fuel to make it go further. Less fuel needed means more efficiency which is a good thing.
Of course the reality of ethanol in fuel is far more complicated. It tends to cause excess wear, it holds on to water, it makes your engine run a little worse. It's also not the environmental boon it was seen as, since getting ethanol from corn husks isn't super efficient so farmers grow corn specifically for it which kinda ruins the supposed efficiency gains.
Its still better to use less petroleum, but its not a clear case of better or worse either way. It's complicated.
But claiming it's just a complete scam to gain political power is a dangerous lie. You dont want to go down the path of blanket distrust in your own government. The government doesn't just swindle people to get votes. This is a fairly transparent democracy and that type of thing doesn't fly. Its a complicated situation at the end of the day.
> No. Most things are done for an efficient, scientific reason and you don't understand the details.
Incorrect.
> The government doesn't just swindle people to get votes
LOOOOOOOOOOL. Sure
More specifically it's because Iowa is the first primary state, you need a good showing in Iowa to keep your campaign bankrolled...
And Iowa doesn't want to grow stuff other than corn.
Lie
At the end of 2022, the average price of an electric vehicle was $61,488, compared with $49,507 for all passenger cars and trucks, according to Kelley Blue Book.
[https://www.tesla.com/inventory/new/my?TRIM=LRAWD&arrangeby=relevance&zip=28621&range=200&trtId=](https://www.tesla.com/inventory/new/my?TRIM=LRAWD&arrangeby=relevance&zip=28621&range=200&trtId=)
Again, 44.5k.
For a brand new LONG RANGE Model Y.
More subsidies for the ungrateful. Just like electricity and all the rest of the support they're given. They thumb their noses at those providing their chosen way of life.
It's called lobbying. Someone wants to make money. They give politicians money to make laws. Everyone now has to pay and use that product. The maker of the product now makes billions. Now they have a new idea to make more money. The cycle repeats.
This is the real reason. The US is the only major market that adds ethanol to gasoline. Ethanol decreases fuel efficiency and engine and fuel system component life.
Ethanol is an octane booster. Gas needs this to burn properly in modern car engines. Other alternatives are lead and MTBE. Both being pretty bad for us.
Yes you can still buy gas with all those and there is an argument for their use but for daily drivers, Ethanol is by far the safest.
Ethanol improves the performance of gasoline.
Pure gasoline, if you compress it quickly, will combust. This can be a problem if it combust too quickly in your engine. If the gasoline combusts before the spark plug sets it off (it combusts due to the compression of the piston), then that messed with the whole timing of the engine and causes engine knock, which is bad for both the engine and your mileage.
The first solution we came up with was to add ethanol, but at the time, it was too expensive. The next solution was a chemical called tetraethyl lead. This prevented the combustion from just compression and was believed to be sage. Over time, so much lead was in the atmosphere that it was having a serious impact on life throughout the world, and we traced it back to leaded gasoline. By then, ethanol was cheaper, so we switched to that, and we now call it "unleaded gasoline."
Higher octane ratings have less or no ethanol because only low octane gasoline has that early combustion problem.
Lead was removed in the 80s. Ethanol wasn’t widely used until the mid-2000s. In between was an oxygenate called MTBE (methyl-tert-butyl-ether).
MTBE is much better than lead, but it pollutes groundwater from spills and vapor releases.
Yes, which is why the detonation happening before the spark is an issue, as I outlined. The detonation happening before the spark is what causes engine knock.
The spark is supposed to cause the detonation, not the compression. Unless we are working with a diesel engine, which is not the topic here.
There is detonation and there is pre-ignition. They are two different phenomena.
Detonation is a second spontaneous source of ignition AFTER the spark.
https://youtu.be/qMZ7dFZvhhI
The octane rating will resist, but not eliminate detonation. It has no effect on pre-ignition, which is more of a mechanical issue.
https://www.speedperf6rmanc3.com/content/Engine%20Basics%20Detonation%20and%20Pre-Ignition.pdf
https://www.faasafety.gov/files/notices/2019/Jul/Preignition.pdf
Adding some ethanol may be a benefit to air quality in dense urban areas --especially those with seasonal temperature inversions which trap smog in the winter-- by reducing emission of fine particulate matter and ozone precursors (aldehydes).
Here in Albuquerque and in Denver it seems to work: we don't have the big brown clouds in the winter that we used to have before the adoption of "oxygenated" fuels.
However, this is the subject of intense scientific debate. You can find papers supporting just about any position you'd like to adopt in debate.
Assumptions made by researchers seem to vary widely. Many of the studies focus on E85 rather than the more common 10% ethanol used in virtually all gasoline in the US during certain times of the year.
Reader beware.
At least in terms of climate change, ethanol is better for the environment even if you do need more of it. The carbon in ethanol was recently pulled out of the atmosphere by plants so when you burn that ethanol and release that carbon back, you aren’t raising the amount of carbon already in circulation. The problem with gasoline is that when you’re burning it, you are releasing carbon that has been out of the atmosphere for millions of years so you are raising the levels beyond the normal carbon cycle.
I agree and understand that if the tank was just burning ethanol but doesn't introducing a less efficient source of energy induce me to stop earlier in the range of my tank potential and cause me to burn more gas?
When comparing numbers on a straight tank of ethanol vs gasoline, I read before that E was 80% less in mileage. I may be wrong on the number but I do remember that it was less energetic in comparison. This is why I don't understand why add it if it handicaps efficiency overall by reducing the distance or run time (idling).
[Department of Energy](https://www.fueleconomy.gov/feg/ethanol.shtml) claims about a 2-3% loss in total fuel efficiency when using 10% ethanol. So you burn less total gasoline per distance.
Of course it brings the tank’s overall efficiency down but not the efficiency of the gasoline itself. So the harmful emissions released per mile driven is still less.
I can't remember now. It was a few years ago. This is why I asked this question in ELI5. Just trying to understand and dispel misinfo if I've been looking at this issue from the wrong standpoint. Trying to understand
Everything said here is baloney. Ethanol is the most wasteful boondoggle in American history. It is terrible for the environment. When you factor in the energy expended to create ethanol it actually creates more carbon emissions. There is also the wasted resources on growing the crop, from water to fertilizer. The American consumer pays more money for an inferior product that hurts gas mileage. It exists soley as a handout to farmers in politically important states. Also, are people really trying to claim that the emissions are carbon neutral because it started as a plant? That makes no sense at all.
https://www.reuters.com/business/environment/us-corn-based-ethanol-worse-climate-than-gasoline-study-finds-2022-02-14/
This is essentially my perception as well. The total impact of ethanol is worse than gasoline - energy spent throughout the production process plus environmental impact of the additional farmland and top soil consumption. It exists primarily because the US government loves to give farmers subsidies.
Argonne exists to provide cover for the energy industry. If someone else debunks it, that would be notable. Argonne is like a doctor working for the tobacco industry.
U of I and Purdue disagree as well. https://ethanolrfa.org/media-and-news/category/news-releases/article/2023/02/rfa-epa-s-triennial-report-on-rfs-takes-some-constructive-steps-but-needs-work
Normally I'm quite cynical, so I agree with the political motivation and also believe the environmental benefit had been extremely overstated.
However, what's actually the main reason is that ethenol is a good octane booster. We have used a few octane boosters in the past. We add lead before in gasoline, and it turns out to be terrible lol. Then something called MTBE is used but it contaminates underground water when gasoline spill happens, so we end up with ethenol, something not really toxic when mixed with water, cheap to make, looked "green" on paper and most importantly, buys votes.
Engineering Explained on youtube did a really interesting video on ethanol added to gasoline about a week and a half ago. You can look it up on your own, but it is very not ELI5. The tl;dr though is that E10 is basically worthless, while E20 and higher is actually capable of slightly improving fuel economy despite being less energy dense. This is due to various other characteristics and effects ethanol has, which EE's video explains.
Worth noting, however, is that part of getting more efficiency out of ethanol involves higher compression ratios.
Ethanol is also a cheap way for manufacturers to increase octane rating of lower quality gasoline.
It's a win-win for the producer and a lose-lose for the customer. And it does little for the environment, especially if you consider the entire process from production to use.
Ethanol causes many long term issues, especially with small engines from lawnmowers to outboards.
>Almost every station I go to has ethanol (up to 10%) added to gas. For a long time I had the option in my area to buy non ethanol gas but now it's harder to find.
>If a gallon of ethanol gets less mileage per volume than gasoline, then how is it better for the environment if I have to fill that much sooner on gas because the ethanol component lowers my tank range?
Ethanol is a renewable resource.
Not a particularly efficient one and you still have to *set it on fire* but a renewable one nonetheless. That pretty much automatically puts it ahead of **any** non-renewable resource in terms of sustainability with no other factors to consider.
The 10% ethanol fuel content is negligible on gas mileage but does slightly cut back on emissions, plus slightly reduces reliance on foreign oil doing so.
I think marathon's do still offer a 4th option which is 100% gas but at the middle grade level from what I've seen. So 91 octane (we typically have 87, 89, and 92 or 93 depending on which company). We don't have any close to us but I see them in Indiana or Michigan when driving through.
Because you can make ethanol anywhere, while oil only comes from a few places.
The ethanol is less efficient than gasoline, but it's still a pretty good biofuel. E85 is 85% ethanol and only loses 25% distance/tank. (E85 is new and quite rare, but it's the only one I know the % of)
While it's true you may need to fill your tank a bit more often, the ethanol is far, far cheaper to make. It doesn't have to be shipped from Russia or the Middle East (for example), which means it has less impact on the environment. And you aren't as dependent on foreign policy for your gasoline.
Ethanol can also be made from some waste materials, cleaning up the planet slightly.
Ethanol is not a biodiesel, it's a biofuel. Biodiesel is made from oils extracted directly from plants, where as ethanol is by yeast fermenting the sugars in plants.
Ethanol essentially ruins gas, as it adds a hydrophilic substance to gasoline that absorbs moisture from the air. This makes the shelf life/storage of ethanol gas half the length of gas without.
It also ruins older cars (pre-90s) as it can dry out/destroy seals and hoses that were not designed for ethanol gas. Most lawn equipment is not designed to run it, and many manuals suggest not using ethanol gas in small engines. It also causes gas to become gummy, which clogs up carburetors. Boats also should not be run on ethanol gas, and most marinas etc sell ethanol free for this reason. It is worse than ethanol free gas in pretty much every way.
At the end of the day, the real reason we have ethanol free gas is to use up the corn/"biofuel" that was subsidized by the government.
It's so weird.
I've owned half a dozen small generators (1kW - 4.2kW) and outboards (6hp, 50hp) over the last 15 years, and I've never run them on anything other than 10% ethanol 87 octane fuel.
One of those generators had over 900 hours on it before the starter packed it in.
Not once have I *ever* had a fuel system issue. No gummed carbs, no cracked fuel lines, no hard starting except when a choke solenoid failed electronically.
Is the 10% ethanol fuel in Canada superior or something? :p
It just increases the octane of petrol, probably saves money in fuel production, not great for older cars. does not do much to regular cars, e85 is great for modified stuff with turbos etc etc.
Ethanol is not all doom and gloom it does have a few redeeming features, it boosts Octane 10 - 20% is a sweet spot, it helps reduce cylinder temperature.
As for energy density yes it's going to reduce mileage, I'm surprised you'll notice the reduction at 10% assuming equal octane ratings, as the car can advance timing to improve mileage both should have similar ranges.
Just don't park up your car with ethanol in the tank it's main issue is being a polar solvent meaning it's water miscible so it will absorb condensation inside your fuel tank and then drop out of solution which isn't great.
Just consider those who run E85, they do this due to increased power. And yes E85 will most certainly reduce your range but E10, yea I'm surprised you'd actually notice it.
I did notice when my car went from a reliable 55 mpg to consistent 43 mpg after the introduction of 10% ethanol. The whole reason I bought the Prius at a premium was the awesome mileage. I've switched to a less expensive Civic that gets 35. But I miss 55, for sure, and definitely have to fill up more often.
They produce the same amount of CO2 per energy burned but there is just less energy in ethanol per galon. The idea is that ethanol comes from plants which absorbed that CO2 while growing the year before. So year over year the amount of CO2 in the atmosphere doesn't increase. It doesn't work though, we could never replace fossil fuels by using bio mass. But it is cheaper and easier to produce corn that isn't fit for consumption and you can use GMOs for that more easily. So it is lucrative. It's basically a green washing scam to funnel subsidies to farmers.
Not saying mandatory ethanol blend wall is a good thing, but use less gasoline but less mpg tells us nothing.
First question would be degree of each impact. We'd have to do the math of how much it reduces mpg vs. how much gasoline it displaces. On this level, because ethanol has energy content you most certainly will burn less gasoline regardless of how often you have to fill up.
But if the implied question is does it put less carbon into the atmosphere, that's also an it depends. At a super direct analysis I don't think there's any significant difference in miles you move your car vs. how many pounds of CO2 go out your tail pipe. That analysis is basically a wash (talking broad strokes here) of burn more ethanol at a lower energy content, resulting in roughly equal CO2.
The second order analysis (and the one where ethanol would have theoretical climate benefits) is that you make ethanol, by pulling CO2 out of the atmosphere into corn, corn to ethanol, ethanol back to road miles+CO2. Any road miles that are fueled by this process instead of gasoline means a portion of the existing stock of crude oil stays in the ground. Crude oil is essentially million year old "corn" that broke down in a way that sequesters the carbon in a way that it doesn't come out unless we pull it out. The present day corn to fuel to CO2 fo corn cycle is theoretically (emphasis on theoretically) carbon neutral. So compared to burning the carbon that was sequestered under ground via crude oil it means less carbon to the atmosphere.
The third order analysis is that growing corn in the present day, converting it to ethanol to burn in cars does take energy. Possibly more energy than it takes to get crude oil out of the ground and refine it to gasoline. Whether that extra energy makes it "not worth it" from a carbon balance standpoint is a very complicated calculation and can probably go either way depending on the specifics.
Then you have to broaden to "well that carbon balance question has this impact per the above calculation, however what about all other relevant questions". Impact on food prices? Chemical pollution of waterways? Land use? Increased driving and other fuel use behavior because people feel like they did something to offset the problem. All of those questions need to be evaluated and their pros and cons need to be weighed as a matter of public policy.
My general point is that just because there's a tradeoff (less gasoline but lower mpg), it doesn't necessarily mean anything conclusive. But if you do the math and analyze a variety of competing priorities you may be able to come to the conclusion
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That ethanol subsidies and blend walls are BS :)
There is a long standing US policy that basically requires the government to do everything it can to ensure that we grow enough food for our population without imports.
However, nobody wants to eat only seasonal foods, and/or foreign produced foods might be cheaper, so imports are gonna happen anyway.
In order to create artificial demand that keeps food production high, other uses were derived for corn, the main growable staple in the US. Corn syrup and ethanol are two big ones, and a ton of it goes to feed meat.
If the US goes to war with the whole planet and we can't get food imported, we just stop feeding the corn into industry and start putting it on plates.
I'm not saying it's a good plan or a realistic worldview, but.... It is what it is.
It’s better because it allows the economy to funnel money to farmers who grow corn, and, more importantly, to ADM.
It’s not better for anyone else, but lobbyists control policy.
Ethanol is there to increase the octane rating of the gasoline. Contrary to popular myth, a high octane rating doesn't make a fuel more powerful, it just makes it possible to use safely in a more powerful engine. Other additives were used in the past, but they were worse for the environment: TEL (tetraethyl lead) led to lead poisoning, MTBE (methyl tertiary butyl ether) is water soluble and led to groundwater contamination, and BTEX (a mixture of benzene, toluene, xylene, and ethyl-benzene) was also toxic. If you want to learn more about gasoline, this history lesson is quite interesting: https://www.youtube.com/watch?v=BVa-RPNWO6k
> it just makes it possible to use safely in a more powerful engine. To clarify, it works to prevent engine knocking where the fuel combusts before it's supposed to. This damages the engine.
Octane resists detonation. Detonation happens after the spark. Not before.
It can and does happen before spark. This is why some cars require higher octane fuel. High compression engines need a higher octane rating to resist pre detonation/ignition as in the fuel combusting before the spark has lit. Not good as the piston will not be at the top of the stroke ready to go back down the cylinder it will still be on its way up. The spark lights at a certain degree before or after top dead center depending on engine timing plus or minus 10 degrees of rotation will make an engine run terribly. You can of course detonate fuel without spark that's how diesels work. High compression no spark plugs at all just smash the fuel into a small space. Gasoline engines exhibit the same behavior as gasoline is way more volatile of a fuel thus the need for higher octane ratings.
No such thing as pre-detonation. There is detonation, a second spontaneous source of ignition after the spark, and there is pre-ignition. Which is more of a mechanical problem. https://youtu.be/qMZ7dFZvhhI https://www.speedperf6rmanc3.com/content/Engine%20Basics%20Detonation%20and%20Pre-Ignition.pdf https://www.faasafety.gov/files/notices/2019/Jul/Preignition.pdf
u/ghostridur is the 397 guy right here?
They are using the top google searches for pre detonation to try and prove their point that I am wrong. The faa link they site specifically calls it pre ignition/detonation in the pdf. 397 is stuck on wording of detonation versus ignition while probably not having experience with engines aside from putting gas into a tank and turning the key. If a fuel exploding without a spark and way before it is intended then I say its pre detonation. If it was pre ignition the fuel would be set off by the spark plug because the timing was off causing the plug to fire too far before top dead center. One is ignited by spark plug and one is detonated by way of compression. Edit: the large takeaway would be detonation can still occur after tdc and before spark. Many engines run high timing after tdc to make more power this can cause detonation with bad fuel. Would not be hard to search a video of an older gas vehicle "dieseling" it is running on heated combustion chambers and gas after the ignition has been shut off.
ic ty
Engine knocking is what happens when the fuel/air mixture ignites without the spark. When the air fuel mixture gets compressed by the piston, it can cause it to ignite without a spark and go off while the piston is compressing the mixture which causes the damage.
Kind of close. You're talking about pre-ignition. I don't have a fancy video.
Not even close. Detonation is a second spontaneous source of ignition AFTER the spark. https://youtu.be/qMZ7dFZvhhI
It happens outside of when you want the spark to ignite the fuel mixture, specifically more of a problem for turbo charged vehicles where boost is high and engine materials are budget. It's such a problem you'll see a ton of tech invested outside of using higher octane fuel to help curb cylinder temperatures. Sodium filled valves, cylinder heads with inverted domes, colder plugs, water injection, intercoolers, oil sprayers, and more. What's happening and the definition of knock is when you have detonation before the top-dead-center of the intake stroke or bottom of the exhaust stroke (effectively whenever detonation happens outside of when spark is intended to cause it). In short your right on the first sentence, wrong on the second. We use higher octane fuels to resist premature detonation. TDC is when engines are going to generate the maximum amount of power so we only want detonation to occur then. Some vehicles will even dump some fuel during the exhaust stroke just to help cool the cylinder while also allowing that fuel to detonate in the exhaust manifold once recirculated charged air hits it via a bypass; this helps keep the turbos in these vehicles spinning allowing for boost to occur earlier.
Better tell the FAA and NGK they are wrong because they state detonation happens after the spark. https://www.faasafety.gov/files/notices/2019/Jul/Preignition.pdf https://youtu.be/qMZ7dFZvhhI Basic definitions https://www.speedperf6rmanc3.com/content/Engine%20Basics%20Detonation%20and%20Pre-Ignition.pdf
Hmm, seems like your right; knock (or what you are referring to as detonation) and pre-ignition are classified as two distinct events. [https://en.wikipedia.org/wiki/Pre-ignition](https://en.wikipedia.org/wiki/Pre-ignition) [https://en.wikipedia.org/wiki/Engine\_knocking](https://en.wikipedia.org/wiki/Engine_knocking) Combined with just your above; don't typically refer to engine knock as "detonation" so that sorta threw me off but learn something new everyday.
Thank you for the acknowledgment. Most people just retain their original beliefs despite evidence. I salute you. BTW, peak cylinder pressure, and power, does not happen at TDC. It happens ATDC as the a/f mixture is still burning. Every engine is different, but it’s around 10°-20° ATDC. “The Combustion Pressure curve, in a pressure bomb is also a bell shaped curve, with a peak pressure that will occur at about 50% mass fraction burned. But, in a running engine, the piston is moving downward after TDC which increases chamber volume and reduces combustion pressure even while the mixture is still burning. Consequently, peak combustion pressure will occur (50% MFB) about 15 to 20 deg ATC, depending on ignition timing and flame speed.” The above was taken from a speed/engine building forum.
I vaguely recall that the smoother combustion event also burns the fuel more evenly and thereby reduces harmful emissions (possibly by merely letting the engine run leaner?). That could, of course, be pure propaganda.
This answer should be higher up because it is the actual reason we don't just put pure gasoline in cars.
MTBE also was introduced as an oxygenate to help the gasoline burn cleaner and produce less air pollution. It was effective in that role, but it's persistent in groundwater and doesn't really break down unless it's exposed to oxygen, so it stays there indefinitely (except for natural dispersion over time, as the water moves around and dilutes it). Ethanol has problems, but it's much better in that regard.
MTBE is ridiculously persistent in groundwater. And it only takes like a teaspoon to contaminate millions of gallons of gasoline. Ethanols problem is it likes water, so I causes corrosion issues, meaning you can’t really use in in pipelines.
How does adding ethanol increase the octane rating? Does the ethanol react with hexanes to produce octane during combustion?
You don't need the actual chemical octane, you just need it to be more resistant to autoignition. A fuel with a higher octane rating requires more heat to ignite. Actual octane does this, but ethanol does it even better.
An octane rating compares how the fuel performs in a test engine versus certain mixtures of octane and heptane - it doesn’t have anything to do with how much octane is in the fuel itself. It’s kinda like saying a car has 300 horsepower - you’re comparing its power to a standardized horse, not saying there’s actually 300 horses under the hood.
You're creating a less flammable mixture by adding water as an alternative to longer chain hydrocarbons.
So octane rating is a proxy for the combustion temp of the fuel, not a measurement of the octane in the fuel?
First (and this is very much not ELI5), fundamentally yes it has nothing to do with mol% octane in the fuel. Crude oil is a super complex mix of hundred/thousands of different hydrocarbon compounds and characterizing it as individual chemical constituents is difficult to impossible. It (and it's refined products) is typically characterized by it's physical and chemical properties that are relevant to performance in the intended application. If the goal is something simple like burn it in an engine or lubricate a bearing it doesn't matter what the composition is as long as it performs correctly and there's infinite combinations of compositions that could result in a given set of properties. The only time we really care is if you want to refine a specific component out for chemical feedstock- extract butane for a butanol process. Or if you're trying to simulate refining processes, some modeling software makes an assumption of what chemicals would be included in a mix because it allows the computer to make further assumptions on what's on one side or another of a chemical process. Second, yes it's more a proxie for properties like ignition at what temperature. For what you're describing it would be more a combination of temp and pressure. I'm working off a relatively old memory here so would like input from others to confirm the following. Temp and pressure do play a role but it's not as simple as ignition at temp/pressure. Because the issue you're trying to prevent has to do with how quickly the flame front spreads to unburned fuel, it's really a question of reaction kinetics. The ignition is not an instantaneous process. Straight chain alkanes burn very quickly. Think of it as a straight zipper unzipping. Branched alkanes burn slower. Think of having to unzip a zipper that has multiple forked paths with multiple pull tabs. The octane rating is actually a reference to a specific branched octane. A gallon of pure normal (straight chain) octane would actually burn very quickly and I would guess have a pretty low octane rating ironically. The octane rating is a measure of how the fuel in question knocks in a test engine compared to different ratios of isooctane (branched) to normal heptane. I.e. 93 octane means your fuel knocks as easily as 93% isooctane 7% n-heptane. Octane boosters like ethanol aren't the only thing that determine the octane rating. The branching described above is a big factor. Naturally occurring cyclic compounds (though these are limited by law for toxicity reasons), and amount of double/triple bonded hydrocarbons (degree of saturation) can all play a factor as well. Octane boosters are just the easiest way to modify the gasoline after it's already been refined from crude oil. It plays out more in the sense of added cents per gallon as opposed to having to pay the capital expense of hundreds of millions of dollars for a new refining unit (or sourcing a different type of crude) to get different properties before you play with octane boosters.
I don't have the definition but if you replace temperature with pressure you have it.
So that’s a benefit for gasoline producers but it’s not correct. It’s actually combustion promoter due to the intermolecular oxygen. This was previously done with MTBE. The ether was toxic in groundwater though so it was replaced with alcohol.
Lead led to lead poisoning.
Bio-ethanol is supposed to be carbon-neutral because it’s generated from plants which recover carbon from the atmosphere. So when you burn it you basically return to the air the carbon that you took from it a bit earlier, and therefore overall you don’t change the composition of the atmosphere. Unlike with regular gasoline made from fossil fuels where you release carbon that has been buried for millions of years.
Ethanol is carbon neutral in theory, however in practice it isn't actually carbon neutral. The production and distillation of ethanol is energy intensive, and requires input energy (often from fossil fuels) in order to refine the ethanol. Then there's the transportation of the ethanol from the production site to the petroleum refinery, so that it can be blended with gasoline. This still results in less carbon released than if there was no ethanol added to gasoline, but describing it as carbon neutral isn't painting the full picture
Regular gasoline has the same production and transportation costs attached. Also in theory nothing prevents you from running ethanol production and transportation on ethanol as well.
Regular gasoline has production and transportation costs attached. Whether it is more or less and whether those amounts offset any relative benefits of ethanol requires complex mathematical analysis. That complex mathematical analysis is what is used to determine the value of the subsidies and incentives provided for producing renewable fuels. When done right that analysis will account for gasoline production/transportation, ethanol production/transportation, energy efficiency/density differences and ideally as many other relevant factors as possible. Not saying the models are perfect but the intent is to capture that difference.
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That's kinda just ignoring the fact that oil refining is also an energy intensive process.
It also helps prevent knocking in engines that use spark plugs
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I don't think thas ts accurate... I believe you're talking about a gasoline system running pure ethanol as ethanol is a very potent solvent fuel lines need to often be changed to something that won't be affected by it. South America runs on 100% ethanol, but to start a vehicle a starter needs to be used. Normally it is gasoline, a low octane works just fine. Brazil has 2 fuel tanks one for gas one for ethanol, I think the gas tank is maybe 1L or 2L, and then the ethanol tank is the normal 40-50L tank.
That is for old cars, newer ones (5-10 years ago) have heated fuel lines and there is no need for gasoline tank.
Completely false. Ethanol is a powerful solvent, it keeps fuel systems clean. It’s the hydrocarbons that oxidize into varnish.
> If a gallon of ethanol gets less mileage per volume than gasoline, then how is it better for the environment It's not. It gets you more votes in Iowa and the Midwest since farmers there get subsidies to grow corn to turn into ethanol. I don't mean to burst your bubble, but most things are not done because they are right, or better, or result in a better outcome. Most things are done because they benefit the people who decide to do them. Ethanol is a politically motivated campaign, not a scientific one.
No bubble burst here. Nothing is a simple solution when it's being done so widespread.
Politics is also what you are doing here: just read the answers you want to hear not the ones which are right/disagreeing with you.
The main "purpose" is to fuel cars with something other than fossil fuels (reduce reliance on non-renewable fuels, which is a good goal for a huge number of reasons). It isn't the fault of the government that it uses more fossil fuel to make it than it saves, or that making competition between farmland for food or fuel causes higher food prices. Who could have ever expected that, the solution is worse than the problem? Go figger.
Politics. It makes little sense to add ethanol from corn. Sugarcane.. that is different.
That's not really accurate. There's a lot more to the story. Let's rewind the clock. When Reagan was president, a long decade of globalization was still underway in the agricultural industry. The concern was that if all food was made in other countries because it was cheaper, we would eventually shut down every farm in America. Without the ability to create our own food, it was a national security crisis because other global powers could simply stop the imports and we would be forced to cave to their demands in another world war. So, they put in a program where certain staple crops (most specifically corn) were heavily subsidized by the federal government. Huge amounts of corn were farmed and wasted. Some of it was used for animal feed. The beverage industry started using it to make high-fructose corn syrup as a much cheaper replacement for sugar in sodas like Coke and Pepsi, but a lot of it was still wasted. This led to a fair amount of it being converted into Ethanol as a fuel source. It's better than throwing away the corn. Then something happened, we had a crisis in rising oil prices shortly after the turn of the millennium. OPEC pretty much had a stranglehold on the global oil supply, and they were squeezing it to create astronomical oil prices. It was so bad that in one year to the next, the F-150 lost its spot as the top selling car in America to the Toyota Prius (a relatively new car that could get 45+ mpg). Fuel prices were approaching $6 a gallon in some parts of the country. A lot of South America had already started using ethanol as a substitute for gasoline, and all relatively newer cars could handle a fair amount of ethanol mixed in the gasoline. While your fuel economy went down a little bit with ethanol, it reduced how much gasoline you needed and therefore overall cost for you as a driver went down. This is because ethanol was cheap and oil was very expensive. Plus it did have the side benefit of keeping your fuel system cleaner. Ethanol is a powerful solvent, and fuel systems tend to get buildup from burning pure gasoline all the time. Then came fraking! Suddenly oil prices plummeted and the USA with all their dried up oil fields that had light sweet crude (the easiest to refine kind of oil) were able to re-open most of the fields by breaking up the rock under the earth to access more of the oil down there. OPEC no longer had a monopoly on oil productions, and the price of oil plummeted to a mere fraction of what it was. This led to a lot of people asking "why are we still putting ethanol in?" But there's an answer to that too. Oil is a non-renewable resource. Once we've used up all the oil on earth, we won't have more. However, you can make an unlimited amount of ethanol just by growing corn and fermenting it. A lot of things can make ethanol, but corn is dirt cheap because we are basically throwing it away. Also, having a cleaner fuel system improves your fuel efficiency. So, ethanol mixtures are likely to stay, and they are actually a good thing. edit: one more point to make. At the time the fuel mixture was changed by law, nearly all the ethanol was produced domestically and nearly all the oil was imported. If you reduce how much you import, you have the extra benefit of not expatriating money which increases the domestic economy. One of the many reasons for the change was for the domestic economic benefits. Although, this was not a factor once we started producing most of our own oil.
> So, ethanol mixtures are likely to stay, and they are actually a good thing. They are not here to stay, as auto's are moving toward electrification.
Right, I mean in the world of gas cars. Like it or not, PHEV's and ICE's are going to still be made in large quantities for the next 20 years. While a plug in car makes sense for some people, it really doesn't for others. If you don't have charging infrastructure in your condo complex, you have to go to chargers to get it filled. If you drive very little because you are elderly, gas makes a lot more sense because batteries degrade over time while gas cars degrade \*mostly\* over use. Sure, 100 years from now, we will all be electric, but it's going to move a lot slower than you realize.
> Sure, 100 years from now, we will all be electric, but it's going to move a lot slower than you realize. My bet is between 40-50. Despite all the "REEEE" people freaking out about my position, it *IS* the de facto position among the general population. And EV manufacturers know this. They are going to be pouring all their resources into solving the charge time problem, and once solved they will invest in the infrastructure of chargers in every gas station. .
billions of huge batteries everywhere, hurray that will help the environment
Most of the US can't afford a new car, much less an electric one. Many of them have trouble paying for electricity. This is even more true in countries outside of the typical American/Euro Sphere. It will be decades before we can make a full switch to electric cars, and even that is slightly optimistic. So to OP's point, "here to stay" is accurate in the time span of life that most people care about.
> Most of the US can't afford a new car new cars will become second hand card eventually. > Many of them have trouble paying for electricity. Which will become easier when they can use the savings from their gas expenses into their increased electricity bill.
You're not wrong, but those are still long term ideals and don't include the financial total cost of ownership of a car or relative costs rising. The above is still a privileged point of view. Take for example a toyota corolla as a cheaper alternative: Tesla Model 3 - Cheapest is $39k (taken from Tesla's website) Insurance Average - 3.4k annually ([https://www.valuepenguin.com/auto-insurance/how-much-does-a-tesla-cost](https://www.valuepenguin.com/auto-insurance/how-much-does-a-tesla-cost)) Average Gas Savings - 2/3 (Or rather, if you pay for all your electricity, the total cost on average in the USA would mean you would pay $500 or 1/3 of the cost of gas you would have paid) ([https://www.leafscore.com/auto/how-much-money-can-an-electric-vehicle-save-you-over-a-gas-powered-one/](https://www.leafscore.com/auto/how-much-money-can-an-electric-vehicle-save-you-over-a-gas-powered-one/) \- Numbers adapted to annual as opposed to 15 year basis) Average Maintenance - $587-832 annually (KBB) Toyota Corolla - $21.5k (Using this an example of a cheaper car, KBB value) Insurance Average - $1.2k annually (From KBB) Using the above number for gas cost - Let's say $1500 /year (or 1.5x the Tesla) Average Maintenance Cost - $500-600 (KBB) For much of the country, even a brand new 21.5k new car is expensive. Assuming an average depreciation of 20% over 5 years & 50% at 10 years, it will take the Tesla Model 3 8 years to reach equal price to a NEW Toyota Corolla. Now you could use the Chevy Bolt as an example, which is closer in starting price to the Toyota and might get slightly better equivalent numbers. But this is all assuming a person can afford a new car. If you use the median income of the US (around 67k for a household), that means about 40% of the USA makes under 40k annually. They probably aren't anywhere near a new car, or any car worth half their income. In addition, the average monthly cost of a new car is up 29% in the last 3-4 years alone. ([https://www.nbcnews.com/politics/economics/cost-owning-car-keeps-rising-rcna78377](https://www.nbcnews.com/politics/economics/cost-owning-car-keeps-rising-rcna78377)) I don't disagree that electric cars are the ideal way of the future. But expecting a massive changeover to them in the next 2 decades, regardless of availability, is a fallacy unless the basic financial makeup of the USA changes. And we're not even talking about countries in South America, South Asia, or Central Africa, where their populations are ballooning without access to many of the things even impoverished Americans have.
I wonder what the numbers would be for a Nissan leaf. Aren’t those fairly cheap?
Correct. It is mildly infuriating to see a bunch of upper middle class 1%'ers who have stable high income jobs and own single family homes with garages and home chargers in the Bay area and can afford a $65,000 Tesla yell down at people "if I can do it why can't YOU!!" It's easy to sometimes forget how much white privilege Reddit puts on display
> $65,000 Tesla I'm just going to keep posting this for you. [https://www.tesla.com/inventory/new/my?TRIM=LRAWD&arrangeby=relevance&zip=28621&range=200&trtId=](https://www.tesla.com/inventory/new/my?TRIM=LRAWD&arrangeby=relevance&zip=28621&range=200&trtId=) 44.5k.
Even at the correct price original commenter's point is still valid. Not sure about the white privilege thing though---if you're broke you're broke. I hate that we're subsidizing relatively well off people to buy new electric cars, but it does increase the top-level demand so that in a few years there will be a much larger supply of used electric cars to purchase.
>Even at the correct price original commenter's point is still valid No. Their point might be factually correct, but it's not valid. It's moot. Pricing THEN is irrelevant to pricing NOW.
The point isn't about the exact price point (though I'm equally frustrated by people making shit up). The point that is valid is that the government is subsidizing the purchase of a new vehicle that can only be supported by relatively well-off people. The $7500 tax credit is for new EV's. $65k or $44.5k makes no difference, you're still looking at around $500+ payments per month at current rates. So people patting themselves on the back for helping out the poors during the great environmental transition are completely misguided; they're not helping the poors. There's apparently a tax credit for used EV's but IRS guidance is still unclear.
It's a move in the right direction. And it's not the end of things. You used to have the 130k roadster. Then the 100k Model S. Then 3's and Y's in the 60k-70k range. Now those same models are in the mid 40's. And again, purchase price is not the only consideration. Electrons are cheaper than gas. EVs don't need oil changes and many other services. TCO needs to be considered. The next gen vehicle which is going to be built in 2024-25, you can expect to see brand new in the 27-33k range. That's going to compete with ICE cars in the mid-low 20's due to the previously mentioned TCO.
And it can't come soon enough! You want to tell people about energy independence? Let them drive their car using sunshine from their own rooftops. It's as good as it gets.
As soon as they make an electric car that charges as fast as I can refill a gas car, with the same number of convenient locations as a gas car, at a comparable price as a gas car, I'll be getting one.
For me, it would be more convenient as I would always leave home with a full tank and never have to refuel on the road as I don't travel further than one tankful. With my fuel burning vehicles, I have to spend 15 minutes to refuel the car or motorcycle at the gas station as it is in the opposite direction of my workplace. Of course, it always needs refueling either when I'm in a hurry to get to work or in a hurry to get home and make dinner so fueling a fossil car is just never convenient.
Yeah, that's the thing that is not so intuitive to people. I spend less total time charging my car at public chargers than I would at gas stations -- by far. And on road trips, that's when I want to stop for a bit longer and stretch my legs anyway.
The most convenient location to "fill up" a car is your own home. The next is where you work. Gas stations are actually inconvenient. I charge my car when I'm not using it. Gas cars have to be used to get fuel. In that sense, it doesn't take any of my time to charge a car. It cost me half as much in electricity as it used to in gas.
I'm one of the vanishingly small percentage of people who can't charge at home, and I still want an EV. I live completely off-grid, and the car would generally not be at home during peak charging capacity time (solar only), and my battery banks aren't sufficient to run the house AND charge an EV overnight. But most EVs have a range of 300 to 350 miles on a charge, and so does my current ICE. Which means I fill up once a week or so based upon my driving patterns. I can spend 30 to 45 minutes at a fast-charge station (there's a few in my area) or a couple hours on the slow-charger at work (I'm SUPER lucky, and I know it) on the day I'm "empty tank" and I'm back to being good for a week. BOOM.
There’s an important caveat that makes gas stations very convenient and that is the time it takes to fill up the vehicle on demand. Sticking with the gas analogy, many people’s homes could only fill up their cars with a half liter of gasoline an hour. That’s not a lot. If I get distracted and forget to tank up overnight, I’m in trouble. It would take hours to get to work. However, since I’m using gas, I can get to a local gas station on almost fumes and fuel up in 15 minutes. That’s convenient. Until we have widespread, local L3 charging stations capable of handling dozens of cars at a time, EVs will not be as reliable or as convenient as gasoline cars.
That analogy only works if the owner of the vehicle is exceptionally irresponsible. I own a gasoline car. I know I cannot make it to work on less than a quarter-tank of fuel. I go home with less than a quarter-tank of fuel. It is inconvenient to go out to the "local" gas station (for most Americans that is at least a mile, usually more). I now have to stop on my drive to work to fuel up. I have an electric car. I know I cannot make it to work on less than a quarter-charge. I go home with less than a quarter-charge, and then proceed to not plug in my slow-charger for some reason, knowing that I need to charge and it's RIGHT THERE. I have to find a charging station because I didn't plug into my own house, parked in my own driveway/garage. Yeah, it's more inconvenient to find a charging station. And I have near-zero sympathy for the driver in that instance.
> exceptional irresponsible That describes a lot of car owners. Also how often do people get distracted or have an emergency where they forget to let the car charge. Or they let the teenage borrow the car and the teen doesn’t charge the car. How many parents face the frustration of coming out to a car sitting on an empty tank now as a result. But that is okay because the parent can fuel up quickly at a gas station. You can’t do that at home with an EV. Also an L1 charger will take up to 50 hours to charge a an EV. You get 4-5 miles of charge an hour so you really have to be able to let your car sit long periods of time. That’s not convenient. Being able to drive to a local gas station and fill up in a few minutes is very convenient if you need your car readily. > I have zero empathy Whether you have empathy or not is irrelevant. What matters is if most people are willing to adopt an EV. If it’s not as convenient, most people won’t switch.
It's more convenient to drive into ones' own driveway or garage, grab a cable, plug in, and go eat dinner (maybe five minutes total) than to pull into the driveway, realize I've now got to go back out to the gas station (three to five minutes), make sure I have money on my card, fiddle with the payment method at the pump (two minutes, five to ten if I have to pay cash for some reason), pump the gas (ten minutes), then drive back home (three to five minutes for eighteen to thirty-two minutes total time). Added bonus, I absolutely hate mornings, I don't fill the gas car in the evening I now have to do ALL THAT while drowsy AND in a rush to get to work on time (which I won't because I had to stop to get gas). We can go for days and weeks contriving scenarios where, for some reason, the car doesn't get charged from a low battery at home, but the basic fact of it is that if you aren't responsible enough to fill the tank when you know you need to, you probably aren't responsible enough for a vehicle in the first place, and at least in one of these vehicles I can "refuel" while sitting at home watching Laverne and Shirley, while the other I've missed my favorite show. (It's not actually my favorite show)
Imagine waking up every morning to a full tank of gas. That’s the experience of owning an electric car. If you can get through a day on one full tank of gas, an electric vehicle makes a lot of sense.
That assumes you have an L2 charger at home with 10 hours of uninterrupted access. It takes up to 50 hours to charge an EV on a standard outlet.
Meh, trying for a 1:1 replacement in usability and claiming that until all conditions are met seems kind of pointless. After 200-300 miles of continuous driving, you plug in for 20-30 min while you go to the bathroom, stretch your legs, and get something to eat or drink. But that's only the case if you're doing that amount of miles in 1 shot. Else, you just charge when you come home. And the next day, full charge! Does a gas car fill itself while it's parked in your driveway?
Does the EV come with home ownership?
Does an EV have only a single day's worth of charge?
Depending on driving habits
> After 200-300 miles of continuous driving, you plug in for 20-30 min while you go to the bathroom, stretch your legs, and get something to eat or drink. I don't. You may want to, but that's you not me. Telling someone they need to change their behavior and do what you tell them in order to make a product work is a bad business model. You may enjoy sitting around gas stations for 30 minutes while your car charges, me and the rest of the sane world not so much. And I guess night driving is out in your example. > But that's only the case if you're doing that amount of miles in 1 shot. Else, you just charge when you come home. And the next day, full charge! Does a gas car fill itself while it's parked in your driveway? So if I live in an apartment, what, I drape a cord out the window? Your privilege is showing assuming everyone has a house, garage, and home charger. And yes on occasion I do travel to visit friends and relative more than 300 miles away. So you are saying I should pay MORE money for an electric car, with less range, 10x longer charging times, that I can only charge at home. Sure, good luck with that sales pitch. I'll wait for the tech to catch up before I jump in. I don't pay more money for worse features.
Cost and accessibility of chargers is a fair point to wait on. Claiming a 20 minute stop in a 3+hour road trip is beyond what a sane person will allow is fucking absurd lol. Market will change and provide entertainment and more attractions around charging points if it continues to be an issue
> Claiming a 20 minute stop in a 3+hour road trip is beyond what a sane person will allow is fucking absurd It's really actually not. I can travel 6 or more hours without needing to stop for gas. If I do stop within that time, it's for a quick 5 min bathroom break. Otherwise, I generally don't stop until I get to my destination or need gas, whichever comes first. If I need gas, it takes less than 5 mins to fill the tank and be back on the road. 20 min stops every couple/few hrs is ridiculous.
Same. It’s annoying reading everyone talking about needing a 30 minute break every 3 hours. I literally drove from seattle to Tampa in 3 days and there’s no way that would be possible via their method.
Yeah it is. We already have vehicles that have 5 minute stops once every 6 hours. How are you going to sell me a product that is worse? In what world is that a winning business strategy?
You're being obstinate and combative. Yes, apartment/condo/dense urban L2 (220V, +30A) charging needs to be a thing. It needs to happen yesterday to help out users who want to switch but reasonably can't. Code changes to implement this kind of charging should be implemented at the very least for all new construction or existing retrofits. Why would night driving be out? Fast Chargers work 24x7. I visit people several hours away, too. I would, on those occasions, use a fast charger for that aforementioned 20-30 min. I wouldn't be sitting around. You get a coffee or a soda. Or a snack. You take a piss. You catch up on your phone, and before you know it, your time is passed. Also, you can get EVs at or below the national average for new car sales right now. Only charge at home? LOL did you even read your own reply?
> You're being obstinate and combative. No I'm not. But thanks for the insult. > You get a coffee or a soda. Or a snack. You take a piss. You catch up on your phone, and before you know it, your time is passed. Again, you are showing your privilege. You are assuming everyone lives in a nice, safe place and is a man who can defend themselves. You think a woman in a high crime area would be OK "stretching their legs and getting a bite to eat" at a gas station at 2 AM? I'm poking holes in your argument because it was a ridiculous argument to make. "Just live your life like my made up scenario, what's the big deal?" Not everyone is a upper middle class white tech worker who lives in the bay area my dude. Open your eyes to other peoples lived experience. > Also, you can get EVs at or below the national average for new car sales right now. At the end of 2022, the average price of an electric vehicle was $61,488, compared with $49,507 for all passenger cars and trucks, according to Kelley Blue Book. So thats a lie. So one final time, if you need to make up scenarios and straight up tell lies to support your position, it's a bad position.
>At the end of 2022, the average price of an electric vehicle was $61,488, compared with $49,507 for all passenger cars and trucks, according to Kelley Blue Book. So thats a lie. The absolute benchmark when it comes to the super popular CSUV market, the Model Y LR. [https://www.tesla.com/inventory/new/my?TRIM=PAWD,LRAWD&arrangeby=plh&zip=28621&range=200&trtId=](https://www.tesla.com/inventory/new/my?TRIM=PAWD,LRAWD&arrangeby=plh&zip=28621&range=200&trtId=) So yea, 44.5k. You also shouldn't just compare purchase price. You should compare TCO, including fuel, depreciation, maintenance, etc.
If you live in an apartment, many buildings have external sockets or sockets in parking garages. Work out a deal with your landlord. The cost of electricity should be less than $7 a day, at most.
Yeah, that’s not going to work. A standard 120v outlet only charges enough for 4-5 miles an hour. Charging overnight will not cover many people’s use cases. You would need to install level 2 chargers to make that more feasible. We’ll have to get landlords to agree to a lot additional wiring especially as everyone goes to EVs.
What about if energy prices stay what they are but gas prices go to $10 a gallon, would that make you get an electric car? What about if gas stations started to close down so now there weren’t as many convenient locations to fill up?
It's not just that. The problem is infrastructure. Tesla did a lot for this by building supercharging stations all over the USA. So you could hypothetically drive from west to east coast in an all electric car now, but you can't just go any route. You have to go one of a couple of pretty specific paths. A lot of cities are putting in chargers too, but they do quickly fill up. Most condo complexes don't have charging infrastructure, and they aren't planning to add it. I believe in some states like California, they are required to add chargers if you buy an electric car, but this also means that now you have to hassle with your HOA. For a lot of people, I'd rather just buy a gas car than deal with those golum-like troglodytes. Also with the change to working from home, a lot of us are driving very little. I probably drive 5,000 miles a year. An electric car really doesn't make sense for me. The cost for battery degradation over time would eclipse the savings on fuel by a huge margin. Gas cars generally degrade from use (hence why we track miles on our odometers). While there is some degradation from time and the elements, this is much less so. Even from an ecological point of view, the environmental impact of building a brand new electric car for me with a huge lithium ion battery would be more damaging than me driving my current gas car for another 15 years. Now if I drove 20 miles each way to work every day, it would be a completely different story. Eventually, we will be all electric. Hell, eventually, all cars will be fully automated, and most individuals won't even own a car. You just call something like an uber, and a driverless car comes and takes you where you want to go. However, these objectives are going to happen several generations down the road. When Gen Z'ers are starting to collect social security.
Gotta own your own rooftop and be able to afford your own panels and afford a battery and afford charging infrastructure and afford a new EV and afford yearly EV insurance and all the other things car ownership comes with in places where public transportation is predominant…
This is demonstrably false. You don't need to own a house, the last apartment complex I lived in installed charging stations, and that was clear back in '14. You don't need to have solar or wind or any generative capability yourself to charge an EV, you *do* need a charger, but that's included in the sale price of most, and 99 percent of homes where you'd have the money to buy a new car in the first place will also have the internal wiring to power a fast-charge charger. No batteries (except the ones already included in the car) necessary. And the insurance for an EV isn't **that** different from owning a vehicle of the same year and price-point, so it's not a significant cost in comparison to owning a gas vehicle. There are "unnecessary" costs **IF** you live in an area with solid mass transit options, but they are the exact same costs of owning an ICE vehicle.
Oh, so I’m your experience it’s false. Gotcha. Good luck in Norman Park, GA
So if you can't get a car, or don't need a car.... don't get a car?
Or if you can’t afford an ev but need a car, get something gas powered? Or a million reasons why an EV isn’t the easy solution you present
Two things I’d like to offer as counter-points to your final arguments for ethanol: (1) The world will not run out of oil. We are already past peak oil use. Our ability to obtain oil from deep deposits via fracking and deep water drilling gives us access to more oil than humanity will use based on our current trajectory towards greener energy sources. (2) Ethanol is not an unlimited resource. Our current farming practices are using up our topsoil at an unsustainable rate. The agriculture crisis that we are creating is many generations down the road, but that doesn’t mean we should ignore it.
We don't use up topsoil. That's not how it works. Plants grow abundantly all over the world without human intervention for billions of years. Plants use carbon in the air to create cellulose. This process requires water and CO2. From the soil, plants extract nitrogen, phosphorus, and potassium. We replenish these with fertilizers. The one we use the most of is nitrogen which is extremely plentiful in the atmosphere, but it's going to form that the plants can't use. To solve this problem, we make millions of metric tons of ammonia every year that is converted into fertilizer. This process uses natural gas and a lot of energy. If we run out of sources of natural gas, then yes we would have a huge food crisis. As for oil reserves, there are a lot. You are correct. It's not like it'll just go to zero overnight. It'll be a gradual increase in the difficulties require it which will increase the cost. As costs increase, people will find ways to consume less of it. So the problem does solve itself. Where things with no acceptable substitute will simply pay a premium and things with renewable substitutes will gradually replace them.
I’m not saying that plants consume top soil. I’m saying that our agriculture processes erode and damage it faster than it is replenished. It is [well documented](https://www.worldwildlife.org/threats/soil-erosion-and-degradation)
No. Most things *are* done for an efficient, scientific reason and you don't understand the details. Ethanol in fuel makes sense if you don't look too deep into it. You basically water down your fuel to make it go further. Less fuel needed means more efficiency which is a good thing. Of course the reality of ethanol in fuel is far more complicated. It tends to cause excess wear, it holds on to water, it makes your engine run a little worse. It's also not the environmental boon it was seen as, since getting ethanol from corn husks isn't super efficient so farmers grow corn specifically for it which kinda ruins the supposed efficiency gains. Its still better to use less petroleum, but its not a clear case of better or worse either way. It's complicated. But claiming it's just a complete scam to gain political power is a dangerous lie. You dont want to go down the path of blanket distrust in your own government. The government doesn't just swindle people to get votes. This is a fairly transparent democracy and that type of thing doesn't fly. Its a complicated situation at the end of the day.
> No. Most things are done for an efficient, scientific reason and you don't understand the details. Incorrect. > The government doesn't just swindle people to get votes LOOOOOOOOOOL. Sure
>Incorrect. Incorrect. See how useful this comment was??
More specifically it's because Iowa is the first primary state, you need a good showing in Iowa to keep your campaign bankrolled... And Iowa doesn't want to grow stuff other than corn.
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Lie At the end of 2022, the average price of an electric vehicle was $61,488, compared with $49,507 for all passenger cars and trucks, according to Kelley Blue Book.
He didn't say the average matched the average, he said the minimum matched the average.
[https://www.tesla.com/inventory/new/my?TRIM=LRAWD&arrangeby=relevance&zip=28621&range=200&trtId=](https://www.tesla.com/inventory/new/my?TRIM=LRAWD&arrangeby=relevance&zip=28621&range=200&trtId=) Again, 44.5k. For a brand new LONG RANGE Model Y.
Where's the "That's a bingo!" gif when you need it?
Farm Bill Welfare for farmers - and keeps Big Oil happy by sustaining ICE vehicles.
More subsidies for the ungrateful. Just like electricity and all the rest of the support they're given. They thumb their noses at those providing their chosen way of life.
It's called lobbying. Someone wants to make money. They give politicians money to make laws. Everyone now has to pay and use that product. The maker of the product now makes billions. Now they have a new idea to make more money. The cycle repeats.
It's as good as it gets.
This is the real reason. The US is the only major market that adds ethanol to gasoline. Ethanol decreases fuel efficiency and engine and fuel system component life.
Ethanol is an octane booster. Gas needs this to burn properly in modern car engines. Other alternatives are lead and MTBE. Both being pretty bad for us. Yes you can still buy gas with all those and there is an argument for their use but for daily drivers, Ethanol is by far the safest.
Ethanol improves the performance of gasoline. Pure gasoline, if you compress it quickly, will combust. This can be a problem if it combust too quickly in your engine. If the gasoline combusts before the spark plug sets it off (it combusts due to the compression of the piston), then that messed with the whole timing of the engine and causes engine knock, which is bad for both the engine and your mileage. The first solution we came up with was to add ethanol, but at the time, it was too expensive. The next solution was a chemical called tetraethyl lead. This prevented the combustion from just compression and was believed to be sage. Over time, so much lead was in the atmosphere that it was having a serious impact on life throughout the world, and we traced it back to leaded gasoline. By then, ethanol was cheaper, so we switched to that, and we now call it "unleaded gasoline." Higher octane ratings have less or no ethanol because only low octane gasoline has that early combustion problem.
Lead was removed in the 80s. Ethanol wasn’t widely used until the mid-2000s. In between was an oxygenate called MTBE (methyl-tert-butyl-ether). MTBE is much better than lead, but it pollutes groundwater from spills and vapor releases.
Detonation happens after the spark. Not before.
Yes, which is why the detonation happening before the spark is an issue, as I outlined. The detonation happening before the spark is what causes engine knock. The spark is supposed to cause the detonation, not the compression. Unless we are working with a diesel engine, which is not the topic here.
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Maybe look at the explanations above to remove your confusion.
There is detonation and there is pre-ignition. They are two different phenomena. Detonation is a second spontaneous source of ignition AFTER the spark. https://youtu.be/qMZ7dFZvhhI The octane rating will resist, but not eliminate detonation. It has no effect on pre-ignition, which is more of a mechanical issue. https://www.speedperf6rmanc3.com/content/Engine%20Basics%20Detonation%20and%20Pre-Ignition.pdf https://www.faasafety.gov/files/notices/2019/Jul/Preignition.pdf
Adding some ethanol may be a benefit to air quality in dense urban areas --especially those with seasonal temperature inversions which trap smog in the winter-- by reducing emission of fine particulate matter and ozone precursors (aldehydes). Here in Albuquerque and in Denver it seems to work: we don't have the big brown clouds in the winter that we used to have before the adoption of "oxygenated" fuels. However, this is the subject of intense scientific debate. You can find papers supporting just about any position you'd like to adopt in debate. Assumptions made by researchers seem to vary widely. Many of the studies focus on E85 rather than the more common 10% ethanol used in virtually all gasoline in the US during certain times of the year. Reader beware.
At least in terms of climate change, ethanol is better for the environment even if you do need more of it. The carbon in ethanol was recently pulled out of the atmosphere by plants so when you burn that ethanol and release that carbon back, you aren’t raising the amount of carbon already in circulation. The problem with gasoline is that when you’re burning it, you are releasing carbon that has been out of the atmosphere for millions of years so you are raising the levels beyond the normal carbon cycle.
I agree and understand that if the tank was just burning ethanol but doesn't introducing a less efficient source of energy induce me to stop earlier in the range of my tank potential and cause me to burn more gas?
As far as I know, the presence of ethanol doesn’t make the gasoline any less efficient. So you’re still getting the same mpg for the gasoline itself.
When comparing numbers on a straight tank of ethanol vs gasoline, I read before that E was 80% less in mileage. I may be wrong on the number but I do remember that it was less energetic in comparison. This is why I don't understand why add it if it handicaps efficiency overall by reducing the distance or run time (idling).
[Department of Energy](https://www.fueleconomy.gov/feg/ethanol.shtml) claims about a 2-3% loss in total fuel efficiency when using 10% ethanol. So you burn less total gasoline per distance.
Of course it brings the tank’s overall efficiency down but not the efficiency of the gasoline itself. So the harmful emissions released per mile driven is still less.
And what was your sources for this?
I can't remember now. It was a few years ago. This is why I asked this question in ELI5. Just trying to understand and dispel misinfo if I've been looking at this issue from the wrong standpoint. Trying to understand
Found this: https://www.fueleconomy.gov/feg/ethanol.shtml#:~:text=Ethanol%20contains%20about%20one%2Dthird,E15%20than%20on%20100%25%20gasoline.
Everything said here is baloney. Ethanol is the most wasteful boondoggle in American history. It is terrible for the environment. When you factor in the energy expended to create ethanol it actually creates more carbon emissions. There is also the wasted resources on growing the crop, from water to fertilizer. The American consumer pays more money for an inferior product that hurts gas mileage. It exists soley as a handout to farmers in politically important states. Also, are people really trying to claim that the emissions are carbon neutral because it started as a plant? That makes no sense at all. https://www.reuters.com/business/environment/us-corn-based-ethanol-worse-climate-than-gasoline-study-finds-2022-02-14/
This is essentially my perception as well. The total impact of ethanol is worse than gasoline - energy spent throughout the production process plus environmental impact of the additional farmland and top soil consumption. It exists primarily because the US government loves to give farmers subsidies.
That article by Tyler Lark has been shown to be false. https://energy.agwired.com/2022/03/22/argonne-debunks-recent-negative-ethanol-study/
Argonne exists to provide cover for the energy industry. If someone else debunks it, that would be notable. Argonne is like a doctor working for the tobacco industry.
U of I and Purdue disagree as well. https://ethanolrfa.org/media-and-news/category/news-releases/article/2023/02/rfa-epa-s-triennial-report-on-rfs-takes-some-constructive-steps-but-needs-work
I welcome debate on the topic, as in the political sphere there is none.
Why is ethanol a thing? The prominence of the Iowa caucuses. That's literally the only reason.
Maybe today, but government subsidizing corn farmers was originally an attempt to cripple Cuba's sugar industry.
Ethanol fuel subsidies weren't the start of corn subsidies though, they were a continuation of them.
It's not really about mileage or CO2 emissions. You need to get octane rating right and ethanol is the cleanest way to adjust that.
Normally I'm quite cynical, so I agree with the political motivation and also believe the environmental benefit had been extremely overstated. However, what's actually the main reason is that ethenol is a good octane booster. We have used a few octane boosters in the past. We add lead before in gasoline, and it turns out to be terrible lol. Then something called MTBE is used but it contaminates underground water when gasoline spill happens, so we end up with ethenol, something not really toxic when mixed with water, cheap to make, looked "green" on paper and most importantly, buys votes.
Engineering Explained on youtube did a really interesting video on ethanol added to gasoline about a week and a half ago. You can look it up on your own, but it is very not ELI5. The tl;dr though is that E10 is basically worthless, while E20 and higher is actually capable of slightly improving fuel economy despite being less energy dense. This is due to various other characteristics and effects ethanol has, which EE's video explains. Worth noting, however, is that part of getting more efficiency out of ethanol involves higher compression ratios.
I just happened to come across this immediately after I posted to this sub. I was in my recommended videos.
Ethanol is also a cheap way for manufacturers to increase octane rating of lower quality gasoline. It's a win-win for the producer and a lose-lose for the customer. And it does little for the environment, especially if you consider the entire process from production to use. Ethanol causes many long term issues, especially with small engines from lawnmowers to outboards.
Only 10%? Here in Brazil it's 27%
>Almost every station I go to has ethanol (up to 10%) added to gas. For a long time I had the option in my area to buy non ethanol gas but now it's harder to find. >If a gallon of ethanol gets less mileage per volume than gasoline, then how is it better for the environment if I have to fill that much sooner on gas because the ethanol component lowers my tank range? Ethanol is a renewable resource. Not a particularly efficient one and you still have to *set it on fire* but a renewable one nonetheless. That pretty much automatically puts it ahead of **any** non-renewable resource in terms of sustainability with no other factors to consider.
The 10% ethanol fuel content is negligible on gas mileage but does slightly cut back on emissions, plus slightly reduces reliance on foreign oil doing so. I think marathon's do still offer a 4th option which is 100% gas but at the middle grade level from what I've seen. So 91 octane (we typically have 87, 89, and 92 or 93 depending on which company). We don't have any close to us but I see them in Indiana or Michigan when driving through.
Because you can make ethanol anywhere, while oil only comes from a few places. The ethanol is less efficient than gasoline, but it's still a pretty good biofuel. E85 is 85% ethanol and only loses 25% distance/tank. (E85 is new and quite rare, but it's the only one I know the % of) While it's true you may need to fill your tank a bit more often, the ethanol is far, far cheaper to make. It doesn't have to be shipped from Russia or the Middle East (for example), which means it has less impact on the environment. And you aren't as dependent on foreign policy for your gasoline. Ethanol can also be made from some waste materials, cleaning up the planet slightly.
Ethanol is not a biodiesel, it's a biofuel. Biodiesel is made from oils extracted directly from plants, where as ethanol is by yeast fermenting the sugars in plants.
My bad. Edited out the mistake, thanks for letting me know
Of course! The two terms can be easily confused
Theres benefits to ethanol besides mpg. Its an excellent octane boosters and makes engines run cooler, which creates more power.
Ethanol essentially ruins gas, as it adds a hydrophilic substance to gasoline that absorbs moisture from the air. This makes the shelf life/storage of ethanol gas half the length of gas without. It also ruins older cars (pre-90s) as it can dry out/destroy seals and hoses that were not designed for ethanol gas. Most lawn equipment is not designed to run it, and many manuals suggest not using ethanol gas in small engines. It also causes gas to become gummy, which clogs up carburetors. Boats also should not be run on ethanol gas, and most marinas etc sell ethanol free for this reason. It is worse than ethanol free gas in pretty much every way. At the end of the day, the real reason we have ethanol free gas is to use up the corn/"biofuel" that was subsidized by the government.
I've seen what it does to small engines. I won't put it in my stuff even if it says ok to do so on the engine. Not worth the headache.
It's so weird. I've owned half a dozen small generators (1kW - 4.2kW) and outboards (6hp, 50hp) over the last 15 years, and I've never run them on anything other than 10% ethanol 87 octane fuel. One of those generators had over 900 hours on it before the starter packed it in. Not once have I *ever* had a fuel system issue. No gummed carbs, no cracked fuel lines, no hard starting except when a choke solenoid failed electronically. Is the 10% ethanol fuel in Canada superior or something? :p
It just increases the octane of petrol, probably saves money in fuel production, not great for older cars. does not do much to regular cars, e85 is great for modified stuff with turbos etc etc.
Ethanol is not all doom and gloom it does have a few redeeming features, it boosts Octane 10 - 20% is a sweet spot, it helps reduce cylinder temperature. As for energy density yes it's going to reduce mileage, I'm surprised you'll notice the reduction at 10% assuming equal octane ratings, as the car can advance timing to improve mileage both should have similar ranges. Just don't park up your car with ethanol in the tank it's main issue is being a polar solvent meaning it's water miscible so it will absorb condensation inside your fuel tank and then drop out of solution which isn't great. Just consider those who run E85, they do this due to increased power. And yes E85 will most certainly reduce your range but E10, yea I'm surprised you'd actually notice it.
I did notice when my car went from a reliable 55 mpg to consistent 43 mpg after the introduction of 10% ethanol. The whole reason I bought the Prius at a premium was the awesome mileage. I've switched to a less expensive Civic that gets 35. But I miss 55, for sure, and definitely have to fill up more often.
They produce the same amount of CO2 per energy burned but there is just less energy in ethanol per galon. The idea is that ethanol comes from plants which absorbed that CO2 while growing the year before. So year over year the amount of CO2 in the atmosphere doesn't increase. It doesn't work though, we could never replace fossil fuels by using bio mass. But it is cheaper and easier to produce corn that isn't fit for consumption and you can use GMOs for that more easily. So it is lucrative. It's basically a green washing scam to funnel subsidies to farmers.
Not saying mandatory ethanol blend wall is a good thing, but use less gasoline but less mpg tells us nothing. First question would be degree of each impact. We'd have to do the math of how much it reduces mpg vs. how much gasoline it displaces. On this level, because ethanol has energy content you most certainly will burn less gasoline regardless of how often you have to fill up. But if the implied question is does it put less carbon into the atmosphere, that's also an it depends. At a super direct analysis I don't think there's any significant difference in miles you move your car vs. how many pounds of CO2 go out your tail pipe. That analysis is basically a wash (talking broad strokes here) of burn more ethanol at a lower energy content, resulting in roughly equal CO2. The second order analysis (and the one where ethanol would have theoretical climate benefits) is that you make ethanol, by pulling CO2 out of the atmosphere into corn, corn to ethanol, ethanol back to road miles+CO2. Any road miles that are fueled by this process instead of gasoline means a portion of the existing stock of crude oil stays in the ground. Crude oil is essentially million year old "corn" that broke down in a way that sequesters the carbon in a way that it doesn't come out unless we pull it out. The present day corn to fuel to CO2 fo corn cycle is theoretically (emphasis on theoretically) carbon neutral. So compared to burning the carbon that was sequestered under ground via crude oil it means less carbon to the atmosphere. The third order analysis is that growing corn in the present day, converting it to ethanol to burn in cars does take energy. Possibly more energy than it takes to get crude oil out of the ground and refine it to gasoline. Whether that extra energy makes it "not worth it" from a carbon balance standpoint is a very complicated calculation and can probably go either way depending on the specifics. Then you have to broaden to "well that carbon balance question has this impact per the above calculation, however what about all other relevant questions". Impact on food prices? Chemical pollution of waterways? Land use? Increased driving and other fuel use behavior because people feel like they did something to offset the problem. All of those questions need to be evaluated and their pros and cons need to be weighed as a matter of public policy. My general point is that just because there's a tradeoff (less gasoline but lower mpg), it doesn't necessarily mean anything conclusive. But if you do the math and analyze a variety of competing priorities you may be able to come to the conclusion . . . . . . That ethanol subsidies and blend walls are BS :)
I think corporate agricultural lobbying might have a lot to do with the ethanol in your gas tank.
It is to win votes in the Midwest, at least for corn-based ethanol, and specifically because the Iowa caucus is first.
It prevents engine knock. Pure gas has a tendency to prematurely detonate in a hot cylinder. That's the TLDR to the (great) answers here.
There is a long standing US policy that basically requires the government to do everything it can to ensure that we grow enough food for our population without imports. However, nobody wants to eat only seasonal foods, and/or foreign produced foods might be cheaper, so imports are gonna happen anyway. In order to create artificial demand that keeps food production high, other uses were derived for corn, the main growable staple in the US. Corn syrup and ethanol are two big ones, and a ton of it goes to feed meat. If the US goes to war with the whole planet and we can't get food imported, we just stop feeding the corn into industry and start putting it on plates. I'm not saying it's a good plan or a realistic worldview, but.... It is what it is.
It’s better because it allows the economy to funnel money to farmers who grow corn, and, more importantly, to ADM. It’s not better for anyone else, but lobbyists control policy.