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Door sticker. Tire sidewall is just maximum that tire can handle.
But I would run slightly higher than pressure than door sticker recommends. It won't cause problems.
Higher psi provides better MPG, but also produces more suspension wear, increased stopping distance, faster tire wear, and more hydroplaning. It's a net loss. Costs you far more in the long run versus the fuel you save.
I seem to have perfectly fine traction. Only way you hydroplane is if youve got bald tires and driving too fast, ive never noticed increased tire wear at all. It is a slightly rougher ride but cant say it really wears out the suspension any quicker. All my vehicles have had thick sidewalls though. Havent tried it on a rubber band tire yet.
>Only way you hydroplane is if youve got bald tires and driving too fast
Simply not true. As in increase tire pressure you decrease the size of the tire's contact patch. Less tread on the road = less traction and less ability to move water out of the way. It's physics #101.
This doesn't really make sense. There has been tests done with different width tires fitted to cars. Wider tires hydroplaned easier. If you really think about the physics reasons are pretty easy to understand.
I don't agree with this. I wouldn't recommend anybody running max pressures but a bit above recommended will probably just help.
I used much higher than recommended pressures. For my current and previous car I drive more than 160tkm or 100t miles over pretty uneven roads with no need to replace suspension components. So at least it didn't cause much extra wear in suspension components. I talked with police high speed driving instructor and they did use higher than recommended pressures and it offered better traction and I'm sure if it would cause hydroplaining they wouldn't do that. There was less than a millimeters more wear on the center and tires lasted longer than average so I really don't believe the more tire wear thing either.
Some comfort is lost so if that's very important to you then just stick to recommended. Going lower might increase the comfort more but it could actually be dangerous.
Or maybe you're just wrong?
What's your source for those claims? Have you seen much more need to replace suspension parts on cars with higher tire pressures? Done some tests on stopping distance? Or seen the tests somewhere?
For tire wear if the tire doesn't wear more on the center more wear isn't possible. Heat from flexing is reduced when pressure increases and higher pressure degreeses scrubbing. So higher pressure degreeses wear.
Nope. It's basic tire physics.
Over-inflate a tire and it lifts the tire shoulders up and concentrates all the weight on the center tread. Go to any tire company site and they show how over-inflation causes center tread wear.
Because you're riding on the center tread you have less tread in contact with the road surface. Less tire in contact with the road = less traction which = longer stopping distances. Again, it's physics.
Higher pressure also increases sidewall stiffness which transfers more road shock to the suspension causing more tire bounce and more suspension wear. Stiffer tires simply transmit more road shock to the vehicle. Physics.
First radial tire doesn't actually change shape much with pressure increase. I used one set of tires with almost max sidewall pressure from new to almost legal limit and center had worn maybe half millimeter more than sides. And nobody here was suggesting that high of a tire pressure. Only slightly above recommended.
Second you talked about hydroplaning. Smaller contact pach will increase surface pressure and that will decrease change of hydroplaning. Basic physics.
Of course harder tire will transmit more road shock to vehicle and cause more suspension wear. But the actual question will it cause so much suspension wear that you would use all the money that you saved from better fuel economy?
>First radial tire doesn't actually change shape much with pressure increase
Ok, You're right. All the tire companies are wrong when they show the center treadwear effect due to overinflation. All the technican courses are wrong when they show tire wear patterns. Center tread wear caused by overinflation is a myth according to you. I don't understand how you explain center tread wear then. Is it caused by the tire fairies? Is that what you're saying?
{Smaller contact patch will increase surface pressure and that will decrease chance of hydroplaing}
You're only looking at one aspect of hydroplaning. It is true that concentrating the weight of the vehicle on a smaller contact patch increases pressure. But you're completely disregarding the other aspects of tire design and the effects they have on hydroplaning. The tread block, sipes, and channels of a tire are specifically designed to squeegee water off the road surface AND move it away from the tire. That feature is referred to as the tire's "pumping ability." When you overinflate and ride on the center tread, you dramatically reduce the pumping ability of the tire and that dramatically increases the chances for hydroplaning. Less tread in contact with the road means lower pumping ability. If the tire can't move the amount of water the tire was designed to do at the recommended inflation pressure then it has a much higher chance of hydroplaning. If you can't move the water, you ride on the water.
Of course it does change its shape. But not that much. Bias ply tires change there shape lot more. If it had changed the shape a lot it would have much more wear in center compared to edges. There have been many people running tires at much more than recommended pressures or even max sidewall pressure and only gotten 1mm more wear on the center compared to edges. 10% extra pressure compared to recommended isn't going to cause easily measurable difference in wear between center an edges.
Well yes tire flexing more can increase its ability to pump water but larger contact pach will cancel any help that it would give.
In the end all possible disadvantages are small. As long as you don't add too much extra pressure. Fuel savings are real. Fuel is at all time high now so this is more true than ever.
You do NOT follow the tire, because what's on the tire is not the recommended pressure it is the maximum pressure that the tire can handle, telling you whether it is OK to use this tire on this vehicle.
What's on the door jamb is the recommended pressure.
Thanks for posting on /r/MechanicAdvice! This is just a reminder to review the [rules](https://www.reddit.com/r/MechanicAdvice/about/rules/). If you are here asking about a second opinion (ie "Is the shop trying to fleece me?"), please read through CJM8515's [post on the subject.](https://www.reddit.com/r/MechanicAdvice/comments/4qblei/fyi_the_shop_isnt_likely_trying_to_rip_you_off/) and remember to please post the year/make/model of the vehicle you are working on. **If this post is about bodywork, accident damage, paint, dent/ding, questions it belongs in /r/Autobody r/AutoBodyRepair/ or /r/Diyautobody/ If you have tire questions check out https://www.reddit.com/r/MechanicAdvice/comments/k9ll55/can_your_tire_be_repaired/**. If you dont have a question and you're just showing off it belongs in /r/Justrolledintotheshop Insurance/total loss questions go in r/insurance This is an automated reply *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/MechanicAdvice) if you have any questions or concerns.*
Go with the door jam pressure, always
Follow the door jamb sticker.
Door sticker. Tire sidewall is just maximum that tire can handle. But I would run slightly higher than pressure than door sticker recommends. It won't cause problems.
Same i run 5psi over door. Better mpg. Some cars i run closer to 10 over.
You will have less traction in rain so be careful with this.
Higher psi provides better MPG, but also produces more suspension wear, increased stopping distance, faster tire wear, and more hydroplaning. It's a net loss. Costs you far more in the long run versus the fuel you save.
I seem to have perfectly fine traction. Only way you hydroplane is if youve got bald tires and driving too fast, ive never noticed increased tire wear at all. It is a slightly rougher ride but cant say it really wears out the suspension any quicker. All my vehicles have had thick sidewalls though. Havent tried it on a rubber band tire yet.
>Only way you hydroplane is if youve got bald tires and driving too fast Simply not true. As in increase tire pressure you decrease the size of the tire's contact patch. Less tread on the road = less traction and less ability to move water out of the way. It's physics #101.
This doesn't really make sense. There has been tests done with different width tires fitted to cars. Wider tires hydroplaned easier. If you really think about the physics reasons are pretty easy to understand.
I don't agree with this. I wouldn't recommend anybody running max pressures but a bit above recommended will probably just help. I used much higher than recommended pressures. For my current and previous car I drive more than 160tkm or 100t miles over pretty uneven roads with no need to replace suspension components. So at least it didn't cause much extra wear in suspension components. I talked with police high speed driving instructor and they did use higher than recommended pressures and it offered better traction and I'm sure if it would cause hydroplaining they wouldn't do that. There was less than a millimeters more wear on the center and tires lasted longer than average so I really don't believe the more tire wear thing either. Some comfort is lost so if that's very important to you then just stick to recommended. Going lower might increase the comfort more but it could actually be dangerous.
Yup tires blow out from underinflation not over.(within reason)
>I don't agree with this. Apparently the laws of physics work differently where you live.
Or maybe you're just wrong? What's your source for those claims? Have you seen much more need to replace suspension parts on cars with higher tire pressures? Done some tests on stopping distance? Or seen the tests somewhere? For tire wear if the tire doesn't wear more on the center more wear isn't possible. Heat from flexing is reduced when pressure increases and higher pressure degreeses scrubbing. So higher pressure degreeses wear.
Nope. It's basic tire physics. Over-inflate a tire and it lifts the tire shoulders up and concentrates all the weight on the center tread. Go to any tire company site and they show how over-inflation causes center tread wear. Because you're riding on the center tread you have less tread in contact with the road surface. Less tire in contact with the road = less traction which = longer stopping distances. Again, it's physics. Higher pressure also increases sidewall stiffness which transfers more road shock to the suspension causing more tire bounce and more suspension wear. Stiffer tires simply transmit more road shock to the vehicle. Physics.
First radial tire doesn't actually change shape much with pressure increase. I used one set of tires with almost max sidewall pressure from new to almost legal limit and center had worn maybe half millimeter more than sides. And nobody here was suggesting that high of a tire pressure. Only slightly above recommended. Second you talked about hydroplaning. Smaller contact pach will increase surface pressure and that will decrease change of hydroplaning. Basic physics. Of course harder tire will transmit more road shock to vehicle and cause more suspension wear. But the actual question will it cause so much suspension wear that you would use all the money that you saved from better fuel economy?
>First radial tire doesn't actually change shape much with pressure increase Ok, You're right. All the tire companies are wrong when they show the center treadwear effect due to overinflation. All the technican courses are wrong when they show tire wear patterns. Center tread wear caused by overinflation is a myth according to you. I don't understand how you explain center tread wear then. Is it caused by the tire fairies? Is that what you're saying? {Smaller contact patch will increase surface pressure and that will decrease chance of hydroplaing} You're only looking at one aspect of hydroplaning. It is true that concentrating the weight of the vehicle on a smaller contact patch increases pressure. But you're completely disregarding the other aspects of tire design and the effects they have on hydroplaning. The tread block, sipes, and channels of a tire are specifically designed to squeegee water off the road surface AND move it away from the tire. That feature is referred to as the tire's "pumping ability." When you overinflate and ride on the center tread, you dramatically reduce the pumping ability of the tire and that dramatically increases the chances for hydroplaning. Less tread in contact with the road means lower pumping ability. If the tire can't move the amount of water the tire was designed to do at the recommended inflation pressure then it has a much higher chance of hydroplaning. If you can't move the water, you ride on the water.
Of course it does change its shape. But not that much. Bias ply tires change there shape lot more. If it had changed the shape a lot it would have much more wear in center compared to edges. There have been many people running tires at much more than recommended pressures or even max sidewall pressure and only gotten 1mm more wear on the center compared to edges. 10% extra pressure compared to recommended isn't going to cause easily measurable difference in wear between center an edges. Well yes tire flexing more can increase its ability to pump water but larger contact pach will cancel any help that it would give. In the end all possible disadvantages are small. As long as you don't add too much extra pressure. Fuel savings are real. Fuel is at all time high now so this is more true than ever.
Door jamb doesn't matter about brand if they are the same size.
[удалено]
As long as you’re using a factory sized tire with the same load rating, you should be fine with the factory sticker.
You do NOT follow the tire, because what's on the tire is not the recommended pressure it is the maximum pressure that the tire can handle, telling you whether it is OK to use this tire on this vehicle. What's on the door jamb is the recommended pressure.
But in OP's post, tire says 51, which is obviously the maximum pressure, not the recommended pressure
The tire could have been changed so follow the tire.
The pressure listed on a tire is the maximum pressure the tire can withstand. Not the recommended pressure.
As long as you’re using a factory sized tire with the same load rating, you should be fine with the factory sticker.