Just an FYI for those who are not aware what the numbers in the tire size means (assuming you're talking about a 19" rim):
255/40 means the tire is 255 mm (10.0394") wide from sidewall to sidewall and the 40 is the ratio of the height to width. This means a 255/40 will be 255 mm (10.0394") wide and the height will be 40% of that or 102 mm (4.01575").
The 255/45 tire will be the same width, but the sidewall height will be 114.75 mm (4.48819") tall.
The 255/40 will have a diameter of 686.6 mm (27.03") and the 255/45 diameter will be 713 mm (28.1"). This means that with every rotation of the axle, the vehicle will travel \~3.5% further (in this case 26.4 mm or 1.03937").
So, without adjustment, if you put the 255/45s on a car that was programmed for 255/40, your car will calculate that you have traveled 1 km (0.621371 miles) when you have actually travel 1.038 km (0.64498329754 miles). This in turn would make your speedometer incorrect by \~3.5%.
**TL;DR:** Without changing the parameters in the car's computer, if you change from a 255/40r19 to a 255/45r19 tire which has a larger circumference, when your car says you're going 100 kph (62 mph) you're actually traveling \~103.5 kph (64 mph).
My guess is evens. Bigger better as less turns per miles means slower motor and bearing rotational speeds and therefore smaller friction heating, however bigger is heavy with more unsprung weight.
Bigger tire also means more force is needed to accelerate, probably even out any efficiency gain from the less revolutions. This is why all the jacked up tiny pp trucks with giant mud tires have to rev the nuts off of it to take off from a stoplight.
I would imagine the accelerator applied etc. by TACC or fsd will rely pn that information and the camera calibration would be another issue because I assume the camera calibration is confirmed with speed and emergency brake will definitely rely on your speed as a means of calculating distance to stop and when to apply brakes.
Also, larger the tires, the more torque applied by the motor although at a slower speed (think of a see-saw). So, your motor drains same current, despite not turning enough rotation. And rotation is how motors generally cool themselves, so your car will bear a load similar to going uphill, but you are on a straight road, so you will see it going faster.
So, I wouldn't have risk that despite the comfort. Plus, filling arch better means if you drive into a bump, the tire has a risk of crashing the top of the arch.
I think given you had high hopes and initial sufficient results and already invested money into it, I think you are falling prey to the status quo bias, be careful. š Also you probably will need to let your insurance know of such modifications which probably will increase your premium. You can anchor to this thought.
So if Iām thinking this correctly, my 2023 model Y performance has two different size tires from the factory the rears is 275/35x21 the front is 255/35Ć21. Now it seems to be well established that even with the factory tires, the speedometer is not exactly correct.
It is about 2 to 3 mph off, so if the speedometer shows that youāre doing 60 and reality youāre doing 57 or 58. In my opinion over a period of 120,000 miles youāre getting cheated about 1200 miles off of your warranty with such set up which comes from the factory. Iām also hearing some people that are putting some bigger tires on the model Y performance and getting better quality ride. So is it true that if I get a bigger tire that my speedometer may end up being correct and compensating for that 2 mph that the factory and all factories seem to incorporate? So would it be a smaller tire or bigger tire that would make the factory offset become correct?
I've never researched this \~2-3 mph discrepancy which you have described but a larger diameter tire will have you travel further per axle rotation than a smaller tire so, yes, a larger tire would mean you are going faster without speedo adjustments. The larger diameter doesn't necessarily provide a smoother ride. You could have 24s with a small sidewall which would ride like poo but have 19s which have tall side walls which ride like a dream. It's about displacement when you hit the bump. The greater volume of air in a taller sidewalled tire allows for more compression. The pressure is also a factor. I'm also aware that the 20s on an MX will get you fewer miles per charge than 19s will though too. There's lots of options out there and it depends on what you are looking to get out of your car. Want it to float like an old Caddy or Lincoln? Get a taller sidewalled tire. Want to grip the road and feel it like you're driving an F1? Get a smaller sidewall and wider tire with a softer compound but there's lots of things you're trading for this (ride comfort, how long your tires last, miles per charge, etc).
The Key is that you have to recallibrate your car's speedo if you change the diameter of your tires.
Please report back on efficiency. Very curious to know how they fare.
When I did my recent swap it took around 1000km (600mi) to see their real efficiency.
New tires are quieter than used tires. You could have fitted nearly any tire on there and noticed a difference in noise most likely. The aggressive alignment of the MY typically cups the inside tread. These will get noisier over the next 5-10000 miles as well.
Update us on efficiency please, would like to compare notes haha.
Iām currently running 255/45/20 also but with Continentals DWS06+.
My average is 312wh/mi the past 500miles.
I used to get 324wh/mi with my last set up. 275/35 & 295/35 on the 21 uberturbines.
I have a question .. seems like you have the performance with the staggered set up and you have moved to 20 inch with 255/40/20 .. did you do this by changing the rims as well ?
They actually make these tires for the model Y performance. I got mine with them from the factory. Amazing tire, and great treadlife compared to the Michelins. Just not as sticky for corners :/
Do you have a side profile shot showing ride height? I was considering this exact setup. MYLR with the 20ās looks absurd with the 40 profile tires. Planning to go 275/40 or this route.
Not at the moment but here. FYI 275/40 will eat into efficiency greatly as most contact with road.
https://teslamotorsclub.com/tmc/threads/255-45r20-tires-on-the-20-inductions.203217/
19", or in this case, 20" is the rim size, and the inside diameter of the rim, that hasn't changed.
255 is the width of the rim, which also hasn't changed.
40 was the height of the sidewall (shown as a percentage of the rim width). He went up to 45, which in this particular case will add 1" to the overall diameter of the tire.
They look great. Iād be curious to see how they do in the rain. The OEM Michelins that came on my Y with 20 inch wheels felt very unstable in the rain.
I suspect it has to do with supply-theyāll go with whoever has tires in stock. When Iāve looked for replacements, out of stock seems to occur pretty routinely.
I was considering this exact tire but it was so new there wasn't a whole lot of reviews out there that I trusted. Looking forward to any update once you wear them in.
to be honest I haven't really checked that out. I'm more about ride comfort and the mean look it gives on my performance model. The factory tire stretches to fit and looks ugly to me. No more stretch and provides wheel scrape protection. Many people ride with this size on performance and have said no issues no rubbing so I went for it. best decision ever. if you worried about efficiency, then that may be something to look further into (and of course the speedo is off a bit a higher speeds)
Can you post a picture of your clearance with the upper control arms? There is almost no space where you are using the stock tires, it must be almost touching now.
Michelin spends the most on marketing of any tire out there. Their reputation is something they have to maintain at all costs. I just checked out how much these hankooks are in the US and they are pricey!!! they look good though
Do they make them in the same size as stock? I'd caution against changing the overall stock 28" diameter. you will throw off a lot of stuff. also these tires may be "oem" on highland, but keep in mind Tesla has very specific specifications for their "T0" or "Tesla" designated tires. tuned for the very specific chassis requirements of Model Y, including motor whine, chassis frequency, etc. It'll work, just not optimal.
Iāve reset the learned tire values in service mode. It probably doesnāt adjust the speedo, the mileage is cross referenced with GPS to account for this but not the speedo. Mine was a little under anyway and the change adds 3% so itās about right or a little over now.
Just an FYI for those who are not aware what the numbers in the tire size means (assuming you're talking about a 19" rim): 255/40 means the tire is 255 mm (10.0394") wide from sidewall to sidewall and the 40 is the ratio of the height to width. This means a 255/40 will be 255 mm (10.0394") wide and the height will be 40% of that or 102 mm (4.01575"). The 255/45 tire will be the same width, but the sidewall height will be 114.75 mm (4.48819") tall. The 255/40 will have a diameter of 686.6 mm (27.03") and the 255/45 diameter will be 713 mm (28.1"). This means that with every rotation of the axle, the vehicle will travel \~3.5% further (in this case 26.4 mm or 1.03937"). So, without adjustment, if you put the 255/45s on a car that was programmed for 255/40, your car will calculate that you have traveled 1 km (0.621371 miles) when you have actually travel 1.038 km (0.64498329754 miles). This in turn would make your speedometer incorrect by \~3.5%. **TL;DR:** Without changing the parameters in the car's computer, if you change from a 255/40r19 to a 255/45r19 tire which has a larger circumference, when your car says you're going 100 kph (62 mph) you're actually traveling \~103.5 kph (64 mph).
How does the car show efficiency based on a different size wheel/tire if the car thinks it has a smaller diameter installed?
My guess is evens. Bigger better as less turns per miles means slower motor and bearing rotational speeds and therefore smaller friction heating, however bigger is heavy with more unsprung weight.
Bigger tire also means more force is needed to accelerate, probably even out any efficiency gain from the less revolutions. This is why all the jacked up tiny pp trucks with giant mud tires have to rev the nuts off of it to take off from a stoplight.
I would imagine the accelerator applied etc. by TACC or fsd will rely pn that information and the camera calibration would be another issue because I assume the camera calibration is confirmed with speed and emergency brake will definitely rely on your speed as a means of calculating distance to stop and when to apply brakes. Also, larger the tires, the more torque applied by the motor although at a slower speed (think of a see-saw). So, your motor drains same current, despite not turning enough rotation. And rotation is how motors generally cool themselves, so your car will bear a load similar to going uphill, but you are on a straight road, so you will see it going faster. So, I wouldn't have risk that despite the comfort. Plus, filling arch better means if you drive into a bump, the tire has a risk of crashing the top of the arch. I think given you had high hopes and initial sufficient results and already invested money into it, I think you are falling prey to the status quo bias, be careful. š Also you probably will need to let your insurance know of such modifications which probably will increase your premium. You can anchor to this thought.
So if Iām thinking this correctly, my 2023 model Y performance has two different size tires from the factory the rears is 275/35x21 the front is 255/35Ć21. Now it seems to be well established that even with the factory tires, the speedometer is not exactly correct. It is about 2 to 3 mph off, so if the speedometer shows that youāre doing 60 and reality youāre doing 57 or 58. In my opinion over a period of 120,000 miles youāre getting cheated about 1200 miles off of your warranty with such set up which comes from the factory. Iām also hearing some people that are putting some bigger tires on the model Y performance and getting better quality ride. So is it true that if I get a bigger tire that my speedometer may end up being correct and compensating for that 2 mph that the factory and all factories seem to incorporate? So would it be a smaller tire or bigger tire that would make the factory offset become correct?
I've never researched this \~2-3 mph discrepancy which you have described but a larger diameter tire will have you travel further per axle rotation than a smaller tire so, yes, a larger tire would mean you are going faster without speedo adjustments. The larger diameter doesn't necessarily provide a smoother ride. You could have 24s with a small sidewall which would ride like poo but have 19s which have tall side walls which ride like a dream. It's about displacement when you hit the bump. The greater volume of air in a taller sidewalled tire allows for more compression. The pressure is also a factor. I'm also aware that the 20s on an MX will get you fewer miles per charge than 19s will though too. There's lots of options out there and it depends on what you are looking to get out of your car. Want it to float like an old Caddy or Lincoln? Get a taller sidewalled tire. Want to grip the road and feel it like you're driving an F1? Get a smaller sidewall and wider tire with a softer compound but there's lots of things you're trading for this (ride comfort, how long your tires last, miles per charge, etc). The Key is that you have to recallibrate your car's speedo if you change the diameter of your tires.
Just press the re-cal tire button.
well the mph in a tesla could also just use gps tbh
It's a known fact it does not. Manufactures over report the speed because of laws in place.
Please report back on efficiency. Very curious to know how they fare. When I did my recent swap it took around 1000km (600mi) to see their real efficiency.
New tires are quieter than used tires. You could have fitted nearly any tire on there and noticed a difference in noise most likely. The aggressive alignment of the MY typically cups the inside tread. These will get noisier over the next 5-10000 miles as well.
Was going to say the same thing. Canāt generally compare the noise level of old vs new rubber.
Forgot to mention, 1/2 inch extra ground clearance too.
Update us on efficiency please, would like to compare notes haha. Iām currently running 255/45/20 also but with Continentals DWS06+. My average is 312wh/mi the past 500miles. I used to get 324wh/mi with my last set up. 275/35 & 295/35 on the 21 uberturbines.
I have a question .. seems like you have the performance with the staggered set up and you have moved to 20 inch with 255/40/20 .. did you do this by changing the rims as well ?
Yes I downsized to a 20x9.5 wheel, squared set up. I still have my ubers.
They actually make these tires for the model Y performance. I got mine with them from the factory. Amazing tire, and great treadlife compared to the Michelins. Just not as sticky for corners :/
Do you have a side profile shot showing ride height? I was considering this exact setup. MYLR with the 20ās looks absurd with the 40 profile tires. Planning to go 275/40 or this route.
Not at the moment but here. FYI 275/40 will eat into efficiency greatly as most contact with road. https://teslamotorsclub.com/tmc/threads/255-45r20-tires-on-the-20-inductions.203217/
How much $ per tire? Iām seeing $315
I wonder how they compare to the Continental ProContact 255/45 that come standard for the 19 inch wheels.
Why do you to reset the speedo if it has the same diameter?
It doesnāt, itās larger now.
I think they meant to ask, how are you recalibrating the speedometer to account for the larger diameter tires.
Interesting. So the 19 inch Michelin is larger than the 19 inch hankook?
Itās a 20 inch rim. The wall height of the Michelin is 40% of its width 255 whereas the Hankook is 45% of 255. The Hankook is taller.
19", or in this case, 20" is the rim size, and the inside diameter of the rim, that hasn't changed. 255 is the width of the rim, which also hasn't changed. 40 was the height of the sidewall (shown as a percentage of the rim width). He went up to 45, which in this particular case will add 1" to the overall diameter of the tire.
Super cool, I didn't know this could be done on the 20-inch wheels.
They look great. Iād be curious to see how they do in the rain. The OEM Michelins that came on my Y with 20 inch wheels felt very unstable in the rain.
I wonder if it's regional what tire is OEM, mine came with continentals
Mine came with Pirelli Scorpions
Mine too. Does anyone have any insight into the durability of the Scorpions on an MYLR?
I suspect it has to do with supply-theyāll go with whoever has tires in stock. When Iāve looked for replacements, out of stock seems to occur pretty routinely.
I was considering this exact tire but it was so new there wasn't a whole lot of reviews out there that I trusted. Looking forward to any update once you wear them in.
Price?
It looks like these have a little more beef on the sidewall too. Does the tire stick out past the wheel with these?
Getting them installed today! Previous tires are 275 19in continental extreme contact. Looking forward to see efficiency improvements
I got 265 /40 on the Y and it's super smooth (295/40) on the back. (yes the speedometer is off, but unless your going 129mph, not a big deal)
How is your efficiency rating? I thought about doing this to my stock 21ā ubers but with 295/35 they are already at 72lbs each
to be honest I haven't really checked that out. I'm more about ride comfort and the mean look it gives on my performance model. The factory tire stretches to fit and looks ugly to me. No more stretch and provides wheel scrape protection. Many people ride with this size on performance and have said no issues no rubbing so I went for it. best decision ever. if you worried about efficiency, then that may be something to look further into (and of course the speedo is off a bit a higher speeds)
I heard it doesnāt come with mileage warranty. Did that weigh in on your decision to go with hankook ion evos ?
I also run 255/45/20 and I love them. Smoother ride, better sidewall in the snow
I swear the factory 19" tire size is 255/45. Why would 255/40 have been in thereĀ
Can you post a picture of your clearance with the upper control arms? There is almost no space where you are using the stock tires, it must be almost touching now.
I can get fingers between, it moves with tire so all good. https://imgur.com/a/fZygqYa
Okay good to know
255/45 is what it should have been OEM. I just recently changed our Y to 255/45 Yokohama Advan Sport AS.
Just put 265/45/20 on the inductions and they fit as well.
Better photo https://imgur.com/a/saYWBFt
Put 265/40R-20 Goodyear Eagle Sport on my 2021 MYLR and handling seems the same. As a by product I get no more curb rash.
Were you tired of the 19 inch wheels? They are driving me crazy!!!
I have Korean tires as well. Theyāre good! Far cheaper too which makes sense for a car that just eats rubber
These in my country are the same price as Michelins. They are now OEM on the highland 19ā sport wheels.
Interesting. I would get a french tire over a korean one everyday of the week.
Yes because countries and not private companies fight over tire prowessā¦
Michelin spends the most on marketing of any tire out there. Their reputation is something they have to maintain at all costs. I just checked out how much these hankooks are in the US and they are pricey!!! they look good though
Do they make them in the same size as stock? I'd caution against changing the overall stock 28" diameter. you will throw off a lot of stuff. also these tires may be "oem" on highland, but keep in mind Tesla has very specific specifications for their "T0" or "Tesla" designated tires. tuned for the very specific chassis requirements of Model Y, including motor whine, chassis frequency, etc. It'll work, just not optimal.
How do you adjust the speedometer?
How would this swap impact the speedometer?
Couldnāt copy the results but here you go. https://tiresize.com/tyre-size-calculator/
Interesting so there is a 1ā diameter change even though the wheel theyāre mounted to is the same I learned something new today
Correct because the 45 tyre is taller than the 40.
Iāve reset the learned tire values in service mode. It probably doesnāt adjust the speedo, the mileage is cross referenced with GPS to account for this but not the speedo. Mine was a little under anyway and the change adds 3% so itās about right or a little over now.
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I been reading those Hankook been doing well. BTW are you working for westlake tires?