What is highest PSI in tires you have used?

[Henry G.]

I have tried 40-50 psi in stock and aftermarket V rated tires. Grip and mileage were slighty better (1-2 mpg) but I am down to 36 psi now, the car just rode too godamn hard. Joints in the interstate were torture, and road noise was up too. I just made a 800 mile round trip at an average of 70 mpg at 37 mpg overall. Thats good enough for me, I think I'm ready for new shocks at 75K miles now, I'm tired of being beaten to death.

[SilverBack]

40 all the time to get the best balance between grip and MPG

[Henry G.]

Yeah I think once I get new shocks that will be the best compromise.

[rningonfumes]

That article, what speed were they going?

I'm at a set 60psi. Have had it there for two sets of tires since 10k and am now at 65k miles. Tires are/were stockies.

[ecc_33]

Man, I can't believe you guys are blowing out tires that high of psi.

[R2D2]

Mazilla,

That article is based on ONE trip at 70 mph using cruise control! Oh yeah, and they were only running 45 psi. Hardly scientific. Apparently, no one was killed, however.

I've been running these pressures for nearly 2 years straight. I know many others have been as well. I know of none who have had any issues outside of a stiffer ride. ALL have gotten uncommonly good tire wear. I can guarantee you this car handles and brakes better at 60 psi.

What exactly are you using as evidence (hopefully some real science here?) to conclude I am a suicidal (and let us not forget potentially homocidal) maniac (Maine-iac?).

If I had found one solitary piece of REAL info that indicated my practice was unsafe I wouldn't even have tried it. Didn't find any. Others who had been running higher pressures for years reported only positives. (Excluding those who died fiery deaths, of course.)

I guess what I'm saying is, at least up to this point, my anecdotal evidence trumps your anecdotal evidence because I know me better than I know you.

R2

[mazilla]

Originally Posted by R2D2

Mazilla,

That article is based on ONE trip at 70 mph using cruise control! Oh yeah, and they were only running 45 psi. Hardly scientific. Apparently, no one was killed, however.

I've been running these pressures for nearly 2 years straight. I know many others have been as well. I know of none who have had any issues outside of a stiffer ride. ALL have gotten uncommonly good tire wear. I can guarantee you this car handles and brakes better at 60 psi.

What exactly are you using as evidence (hopefully some real science here?) to conclude I am a suicidal (and let us not forget potentially homocidal) maniac (Maine-iac?).

If I had found one solitary piece of REAL info that indicated my practice was unsafe I wouldn't even have tried it. Didn't find any. Others who had been running higher pressures for years reported only positives. (Excluding those who died fiery deaths, of course.)

I guess what I'm saying is, at least up to this point, my anecdotal evidence trumps your anecdotal evidence because I know me better than I know you.

R2

Only one of us worked as a tech for a major tire chain for a half dozen years...so you're anecdotal evidence is worth jack when it comes to the experience of somebody who actually worked in the business. Did you go to tire school too?

In a game of Russian roulette I still have 5 chances not to get shot...doesn't make me smart for playing.

If you can find me one piece of info that says it is safe, we can go from there...because I can fill this page with links to places that say it's STUPID.

To reiterate, as far as I'm concerned you can drive your car off a cliff, as long as the only person hurt is you. These stupid games risk the lives of every car you might some day collide with, maybe it wont be today or tomorrow, maybe it will be 20 sets of tires down the road...but the negative effects are there and you cannot escape that.People that play these games are the reason we have so many laws on the books...because you can't tell the difference between a good idea and a bad one.

[rningonfumes]

Very well, give us some data on accidents related to tire over inflation. I know there are some out there with under inflation.

Enlighten us poor fools for which the gub-ment are protecting hour sefs frum us-sulfs.

[mazilla]

Originally Posted by rningonfumes

Very well, give us some data on accidents related to tire over inflation. I know there are some out there with under inflation.

Enlighten us poor fools for which the gub-ment are protecting hour sefs frum us-sulfs.

There is likely no specific data on over inflation, just like there is no specific data on under inflation...however, the lack of numbers should not alleviate one of the responsibility of using ones brain when determining a good idea vs. a bad one. There are no positives(outside of a race track) for running dangerously high tire pressure, and there is no published data available to back your claims that it's a good idea.

You're fighting physics and common sense, neither battle will end in victory.

NHTSA's current crash files do not contain any direct evidence that points to low tire pressure(or high pressure) as the cause of any particular crash. (19) However, this lack of data does not imply that low tire pressure(or high pressure) does not cause or contribute to any crashes. The agency believes that it simply reflects the fact that measurements of tire pressure are not among the vehicle information included in the crash reports received by the agency and placed in its crash data bases. (20)

The only tire-related data element in the agency's crash databases is "flat tire or blowout." However, even in crashes for which a flat tire or blowout is reported, crash investigators cannot tell whether low(or high) tire pressure contributed to the tire failure.

The agency examined its crash files to gather information on tire-related problems that resulted in crashes. The NASS-CDS has trained investigators who collect data on a sample of tow-away crashes around the United States. These data can be weighted to generate national estimates.

The NASS-CDS General Vehicle Form contains a value indicating vehicle loss of control due to a blowout or flat tire. This value is used only when a vehicle's tire went flat, causing a loss of control of the vehicle and a crash. The value is not used for cases in which one or more of a vehicle's tires were under-inflated, preventing the vehicle from performing as well as it could have in an emergency situation.

Mine in bold


Somebody had to input common sense into this thread, so random people searching the net don't see this thread and thinks it's a good idea to copy you folks.

[rl67pinoy]

on my 215/40 r17 its 37psi 36 is the max written on sidewall of my tires

[rningonfumes]

NHTSA's current crash files do not contain any direct evidence that points to low tire pressure(or high pressure) as the cause of any particular crash. (19) However, this lack of data does not imply that low tire pressure(or high pressure) does not cause or contribute to any crashes. The agency believes that it simply reflects the fact that measurements of tire pressure are not among the vehicle information included in the crash reports received by the agency and placed in its crash data bases. (20)

The only tire-related data element in the agency's crash databases is "flat tire or blowout." However, even in crashes for which a flat tire or blowout is reported, crash investigators cannot tell whether low(or high) tire pressure contributed to the tire failure.

The agency examined its crash files to gather information on tire-related problems that resulted in crashes. The NASS-CDS has trained investigators who collect data on a sample of tow-away crashes around the United States. These data can be weighted to generate national estimates.

The NASS-CDS General Vehicle Form contains a value indicating vehicle loss of control due to a blowout or flat tire. This value is used only when a vehicle's tire went flat, causing a loss of control of the vehicle and a crash. The value is not used for cases in which one or more of a vehicle's tires were under-inflated, preventing the vehicle from performing as well as it could have in an emergency situation.

Mine in bold.

These studies were after the fact, thats why they couldn't directly relate to tire pressure. "Either low or high pressure" is a wide spectrum. I respect that you have experience in the subject, but R2, others, and I haven't exactly blindly upped our pressures. Not speaking for the others but I've read the various forums... I haven't read about any incidents related to overinflation. People have done this for at least 5 years now, of that population of people doing this, I have not heard of any incidences. It's not to say that it proves my stance, it's saying that without direct info/studies, that is what I have to go on.

I do understand basic physics, you're saying something will give. Of course something will give, but the picture most people think of in their mind about tires popping is like that of a overblown balloon. It's not going to pop like a balloon. I've had a few punctures...at the high psi (granted at low or no speed), they don't "pop", otherwise I would have been scared shitless. What a majority of us (those who do over inflate) are saying is that there is a higher limit than what's on the sidewall.

Then there are the many differences on the max psi for different tires. Manufacturers have come out with 50psi max tires in their "fuel economy" tires. Those manufactureres haven't exactly explained what is so different, or what they did to "provide safety" at the higher psi.

Someone please scientifically test this out for us!?! We are not unreasonable, we will take data.


Edit:

Originally Posted by mazilla

Somebody had to input common sense into this thread, so random people searching the net don't see this thread and thinks it's a good idea to copy you folks.

There is a lot more damage out beyond YW for the brainless copy cats. For the most part if someone asks me, I tell them to do the max on the sidewall and only as high as they're comfortable with, and I'll find out later that they stopped at 5 under the max. Why do I do that? The folks who usually ask this question just want confirmation for what they already know and don't really want to be scared. Now if someone gave me a hint that they knew some basics about hypermiling, I would steer the conversation a different direction.

[R2D2]

Originally Posted by mazilla

Only one of us worked as a tech for a major tire chain for a half dozen years...so you're anecdotal evidence is worth jack when it comes to the experience of somebody who actually worked in the business. Did you go to tire school too?

In a game of Russian roulette I still have 5 chances not to get shot...doesn't make me smart for playing.

If you can find me one piece of info that says it is safe, we can go from there...because I can fill this page with links to places that say it's STUPID.

To reiterate, as far as I'm concerned you can drive your car off a cliff, as long as the only person hurt is you. These stupid games risk the lives of every car you might some day collide with, maybe it wont be today or tomorrow, maybe it will be 20 sets of tires down the road...but the negative effects are there and you cannot escape that.People that play these games are the reason we have so many laws on the books...because you can't tell the difference between a good idea and a bad one.

Round and round we go. I would argue my anecdotal evidence is worth plenty more than "jack" because I've got 2 years of daily real world experience under these conditions not a bunch of regurgitated generalizations.

Any test data from "tire school"? Can you share data you've collected working at a tire shop related to tire inflation that apparently is not even collectible by NHTSA? Anything? "Given tire size xyz for every psi over max sidewall a tire is 1 point Blah blah more likely to fail" or "takes an additional x ft of stopping distance" or anything such? If our practices are so blatantly "stupid" surely there is plenty of such data available that I have overlooked somehow.

Thanks for the compassion. The urge to drive off a cliff has never presented itself until this thread came along. Good thing, I may have injured an innocent ant or maggot. Keep in mind I very concisely answered the OP's question. I provided a fact, plain and simple. I wasn't advocating the practice, nor do I recommend the practice.

I hope my 1st issue is 20 sets of tires down the road! I bet any user of tires would take those odds, period! Doesn't seem to add credence to the fact my habits are so dangerous.

[R2D2]

Almost forgot-to the OP I run 120 psi in my road bike tires.

R2

[mazilla]

R2...when something happens you make sure you have the intestinal fortitude to tell te investigators(if you still have the ability) that you run your tire pressure far beyond the Mfg safety guidlines, then maybe we can start to get some real data. I have the feeling people tend not to mention that they are the cause of the problem after an accident, hence no data, nobody like going to prison or being sued. Make sure you reference this thread, let them know you were warned and take full responsibility for your actions.

[Ace]

Originally Posted by R2D2

Almost forgot-to the OP I run 120 psi in my road bike tires.

R2

then run with 120 psi in your yaris.

why stop at 60.

[Uber_Otter]

Can you just get some smaller Light truck tires? I run 35psi in my XA but I run 65 psi in my 68 vw bus, they require it or they get all bendy.

[malibuguy]

i just upped mine to 52 cold

[docB]

Been reading this. Race cars actually run the pressure that will maximize grip. Rarely is fuel economy an issue. Last I read, Formula 1 cars go to the grid with less than 20 psi. The tire is a vital component of the suspension. Usually a pyrometer is used and the shocks, springs, and alignment to get the maximum use from the entire tread. I have never had to exceed rated sidewall for autocrossing. race or street tires.
I run 42 front and 35 rear. Any higher in the back and the ABS is kinking in all the time. Tire wear appears reasonable and the car feels more planted than at the factory recommendations.
As for the super presuures, the design of the tire really makes these unsafe. It just is bad all around the run the big numbers. Suspension takes a bigger beating, breaking distances usually increase. I know I'll never do it.
doc