Tire Pressure Max

[deebrown]

I heard that inflating the tires to max pressure will increase stability and I would like to try that out - does anyone know what the tire pressure max is on the P185/60R15 that come with the car?

[ROCKLANDTOYOTA]

44 LBS....

[seymour201]

It says it right on the tire

[BailOut]

We hashed this all out in another thread that you can search for if you'd like deeper information, but here's the skinny:

Max sidewall pressure is the *minimum* pressure you should use on the Yaris. Several of us on CleanMPG.com run the RE92's at 60 PSI and have gotten not only nice MPG increases (due to lower rolling resistance) but much greater life out of the tires (the first of us to go to 60 PSI just hit 85,000 miles on the original tires - that's unheard of at 32 PSI).

Toyota's recommendation of 32 PSI is based solely on a comfortable, cushy ride rather than anything to do with performance, stability, tire wear, etc.

[jamal1984]

Originally Posted by BailOut

We hashed this all out in another thread that you can search for if you'd like deeper information, but here's the skinny:

Max sidewall pressure is the *minimum* pressure you should use on the Yaris. Several of us on CleanMPG.com run the RE92's at 60 PSI and have gotten not only nice MPG increases (due to lower rolling resistance) but much greater life out of the tires (the first of us to go to 60 PSI just hit 85,000 miles on the original tires - that's unheard of at 32 PSI).

Toyota's recommendation of 32 PSI is based solely on a comfortable, cushy ride rather than anything to do with performance, stability, tire wear, etc.

so what you said is we can put the pressure on the yaris to 60psi? my is at 40 now, i'm worry that i'm pump over 44 the tires will blow in my face, that is one scary shit.

If it true i will do it for sure man.

[5spBlazer]

Im running 50PSI right now.

[AlphaFox]

what kind of MPG increases are you seeing running at 50 or 60 psi? (up from stock)

[brickhardmeat]

There is a "thingy" in your glove box called an Owner's Manual, comes "free" with the Yaris. Try opening it up. Theres lots of words in there and "stuff"

[BailOut]

Originally Posted by AlphaFox

what kind of MPG increases are you seeing running at 50 or 60 psi? (up from stock)

That's a hard one to answer because your driving style really plays into it. If you're a regular, everyday kind of driver then you will see maybe 0.5 - 2 MPG, just because it's easier for your engine to make the car roll if it doesn't have to fight the tires so much.

If you hypermile then the benefits shoot through the roof. For example, on my commute home there's a section of the mountain road that is just very slightly downhill for almost a mile. I used to have to use fuel in this area but with the tires at 60 PSI I can turn off the engine (and then go back to Ignition II to keep PS/PB for a while) and coast that entire section without dropping speed. I can pull a similar stunt for about another mile at the bottom of the mountain after going through the clover leaf on-ramp. I can use it twice again in my subdivision for another half mile each time after accelerating to 40 in a 45 MPH zone. I can stealth coast from the main subdivision road through 4 90-degree turns and right up my driveway and into my garage.

[PetersRedYaris]

Not to bring you guys down, but, this is a really bad idea. Max pressure is called that for a reason. You do know your tires heat up with highway speeds so even putting them at 44 means they are running far higher than that with sustained speed. Setting them at 60PSI means they could go over 70 with summer heat and fast driving. Blow-out time!

[BailOut]

Originally Posted by PetersRedYaris

Not to bring you guys down, but, this is a really bad idea. Max pressure is called that for a reason. You do know your tires heat up with highway speeds so even putting them at 44 means they are running far higher than that with sustained speed. Setting them at 60PSI means they could go over 70 with summer heat and fast driving. Blow-out time!

Back in the 1970's you would have been right, Peter. However, since that time consumer tires have been steel belted which prevents this from happening. The worst that could happen on just about any modern tire is some uneven and/or early tread wear.

I commute over a mountain every day in snow or sun at 60 PSI without issue. As I mentioned earlier a fellow hypermiler who does a lot of highway driving just hit 85,000 miles on his RE92s, which is literally impossible at 32 PSI. We are just 2 out of a pool of folks that have been running at 60 PSI for quite some time now not only without issue but with several tangible benefits.

[SailDesign]

I'm with Peter on this one. Max pressure is listed so that you know what NOT to inflate above, for safety reasons. You may indeed get better mpg, but other things like braking and cornering will be adversely affected, and should you have an accident through a blow-out, and it is found all your other tires are over-inflated, you will have a hell of a fight with your insurers.
Would you ride with 11 other people in an elevator rated for 6, just because it saved energy going down? I thought not.....
Getting another 2 mpg out of a car that is already capable of over 35 is not enough of an incentive, IMNSFHO

[BailOut]

Originally Posted by SailDesign

... but other things like braking and cornering will be adversely affected, and should you have an accident through a blow-out, and it is found all your other tires are over-inflated, you will have a hell of a fight with your insurers...

Actually, the inverse is true about braking and cornering since there is no tire sag to deal with. The higher pressure offers much better handling, not worse. Try it for yourself.

You have a valid point about insurance companies because they are generally uneducated about such matters. I do not bow to a lack of education... I educate the uneducated.

[Chris07LB]

Originally Posted by BailOut

(the first of us to go to 60 PSI just hit 85,000 miles on the original tires - that's unheard of at 32 PSI).

For real? On your '07 you have 85k already?

[Doc Zaius]

Might be an '06 if its from Canada... we got them earlier than you guys.

But wow... 60 PSI... thats nuts. I won't feel so bad about overinflating a little bit now.

(also the first time I'ver heard the term hypermiler!)

[SailDesign]

Originally Posted by BailOut

Actually, the inverse is true about braking and cornering since there is no tire sag to deal with. The higher pressure offers much better handling, not worse. Try it for yourself.

You have a valid point about insurance companies because they are generally uneducated about such matters. I do not bow to a lack of education... I educate the uneducated.

Up to a point, higher pressure helps. I'm at 43psi right now on 205/45-16s, and it works well even in rain. But, too high a pressure reduces the contact patch with no increase in coefficient of friction, since the tyre/tire becomes more brittle at a certain load level and fractures (at an almost microscopic level) rather than grips. The trick is in finding the "sweet spot" for your tyres and car. There was a good article on tyre physics in... someone help me out, here - one of the Sports Compact/GrassRoots Motorsport/Modified mags recently. Well worth reading.
"Inverse"? Is that the same as "opposite", but for edjimacated folks?

[Black Yaris]

you guys running 60 psi are not the brightest bulbs in the pack are ya... expacially on the shit ass stock potenza that came stock on the car, 1st the car has to ride like a brick, 2nd the is a safty issue, by over inflating the tires you risk seperating the tire and at that pressure it would most likely blow out.
general rule of thumb, over inflating is not a good idea

BailOut, I think you would be safer doing a "bailout" on the freeway than driving with 60 psi

and for that guy that got 85k on his stock potenza's... I am sure he had plenty of tread left.... on the outside edge of his tire, there had to be non left on the inside at that psi, and plus the increased psi from heating them up on the e-way in NV (1psi per 10 deg)

[eTiMaGo]

BailOut, I think you need to procure some tread pictures or other proof if you wanna continue with this