Tire Pressure

[landtoy80]

The tire pressure on the Supra says 28 psi.
I assume thats with a 35 psi max factory tire and I assume most car tires have around 35 psi max.

I have General tires with a max 44 psi.
When a tire has a higher max pressure of 35 psi do you still set the psi to factory setting?
I am having more wear on the sides then the center. The center is good and the sides are down the wear mark.

I have the same question/problem with my 96 Camry and problem
My Traction TA's always wear out on the out side part of the tread. Its even on both sides of the tire and on both left and right side of car. The tread in the center always had plenty of tread when the sides wore out.
Do I want to increase the tire pressure on this tire to get more center wear? Will going over 29/32 psi cause loss of control.

How do you determine what pressure to set at with a higher psi tire?

 

[SySt]

Sounds like you do want to increase tire pressure. Just because the factory tires are supposed to have 28psi doesn't mean different tires on the same car should. Try running 35+ psi. There should be no problem with driving the car. If anything the tires will provide more traction due to more even weight distribution across the tread of the tire.

 

[AJ'S 88NA]

You need to run a little more pressure with low profile tires. I run close to the max. pressure on the tires. This keeps the tire flater on the road. It's the opposite of what you would think, if the center is wearing you need a little more pressure. Take a look at your tires at the top you'll see what I mean, you will see the center concave with 32 lbs. So you are accually running on the sides. I drop mine to 38-40lbs if I go to the track, the sidewalls are still stiff enough, drop below that and I get sloppy handling. On the track they tend to get a little hotter and the pressure goes up.

It will stiffen the sidewalls and accually give you more control without the sloppy play in the sidewall. If your max pressure is 44lbs I'd run at least 40-42lbs. You'll get better mileage out of the tires and you see a little better gas mileage.

Just what I've observed over the years with lower profile tires.

 

[landtoy80]

I read in the owners manual, if you run at speeds over 75 mpg, add 8psi but don't go over the max tire pressure.
When I checked them it was at 22 psi. I increased that to the sticker in the glove box 28 psi.
I now aired them to 44 psi to see what happens.

 

[IJ.]

I run 2 psi under max here.
(helps save the rims with lo profile rubber)

 

[pato]

ive got potenza re001's on 235/40/18 and 215/40/18,
i run 40psi,

thats, what the tyre dealer told me i should run to get maximum wear out of them

 

[Who]

See the link and image that shows what happens to a tire under low and high pressure.
Follow the tire label on the tire. The sticker on the door jamb is only good for
the factory tires that come with the car. The higher the pressure the less the tire sidewall will bend or roll on the rim. When the the sidewall rolls you lose contact patch and air leaks out. Most importantly a tire low on pressure will run hot. Heat is a tires worst enemy. I will ride a over inflated tire any day over a under inflated tire. I have run heavy loads and equipment on trailers and a low pressure tire will dissolve long before a properly or overinflated tire.

Take note that this is a recommendation for street use & daily driver scenario.

Tire pressure.

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[sneakypete]

i run 42psi in the front and 40psi in the back. this of course is after the tire is heated up.

 

[AJ'S 88NA]

i run 42psi in the front and 40psi in the back. this of course is after the tire is heated up.

That's what I run cold. Which I think is when you are suppose to check pressure.

 

[DegreE]

Toyo Proxies on my Sawblades.

40psi cold.

 

[suprageezer]

Here's an excel spreadsheet I made, you add in your numbers and it calculates your pressures. I've used this for years on my Supra and two sets of Goodyear F1's and they have worn perfectly even their entire lives never having to be rotated. One thing I do different is increase the air pressure when driving in rain to reduce the footprint which increase the speed at which my tires hydroplane. When the rain is gone I go back to the numbers in the chart.

 

[sneakypete]

That's what I run cold. Which I think is when you are suppose to check pressure.

well, when you start driving, wont the tire heat up and raise pressure over the max tire pressure?

 

[AJ'S 88NA]

well, when you start driving, wont the tire heat up and raise pressure over the max tire pressure?

Yes. Most tires say on them "Max cold pressure". You always check them cold as they will always be the same temp. more or less. After you run them more than a mile they heat up, and depending how far you drive they will heat up even more which will change the pressure. That's why you always check them cold.

 

[Poodles]

filling with nitrogen helps stop the variation in pressure from tire temps...

 

[sneakypete]

filling with nitrogen helps stop the variation in pressure from tire temps...

sweet.... now i just need to find a tank of nitrogen

 

[starscream5000]

I gots teh nawz in muh wheel man! Wanna race? :naughty:

 

[daught]

If you run over 40 PSI, don't you put too much stress on ball joints/tie rods? Also when hitting a pot hole your handling should be worse. I have no doubt that on a track much higher pressures can be used with positive effects but on the street I am not so sure.

 

[annoyingrob]

sweet.... now i just need to find a tank of nitrogen

Welding supply shops. Buy or rent a tank for a few hundred, then it costs next to nothing to refill. Regulators can be had for cheap on ebay.

 

[Poodles]

Look around, quite a few tire places do it as the nitrogen generators are cheap these days.

Nitrogen makes up most of our air, is inert, and has other benefits.

- Doesn't rust/corrode the wheel
- Keeps more stable pressures because it's not affected by heat
- Doesn't leak out as easily

Should see better gas milage as properly inflated tires reduce drag.

 

[sneakypete]

getting tank shouldnt be a problem... getting the regulator is expensive in my experience (at least with oxygen). i will check with my company to see if we can get the regulator in addition to the tank. also to see if i can get a fitting that can attach to the regulator hose that will fit on to the tire fill attachment.