Tire Pressure Question
 

I noticed my tires seem to be wearing more in the middle indicating their overinflated. I keep them inflated around 34-35 lbs but once they build up pressure, on a hot day driving on the highway, this pressure will increase to 38-40 lbs.

My question is, what do you guys have them set at? Please specify if this is at startup when tires are low on pressure or if its after driving.

1) you didn't state what size and brand tires you're using. what about wheel size? problem on all tires, front or rear?


2) you always set the inflation pressure "cold". it naturally increases as you drive due to heating of the tire.

They're the Potenza's on factory 18" touring wheels.

35 cold.

What kind of gauge are you using? If you are using one of the pen type, pitch it out. They are next to worthless and highly inaccurate. I've got a dial type and I know there are a few other styles that are good also.

I use a dial type like you're referring to. I've always inflated them to 35 but since I noticed more treadwear in the center of the tire, I began to think this might be too high.

Could be. Especially since you live in Dallas. It doesn't take long to for the tires to heat up in that kind of climate.
I kept an eye on my tires a few years ago and the pressures would go up into the low 40s when the temps were in the 90s outside.

I agree with TreeFiddyZee. Check your measuring instrument against a known good-quality device. It’s possible your instrument is not calibrated properly.

Better quality instruments have calibration settings.

--Spike

I think its calibrated correctly since its exactly as Treefiddy is describing. I got them set at 35 cold, but the heat in the summer and driving on the highway, I see it creep up to 40-41. I was thinking about dropping them down to 33 or so cold in order to compensate for the heat.

Try it and see how it works out... you'll never know if you never try!

Photos always helpful.

That's normal for the Potenzas. My OEM tires wore more in the center on the rear tires but I never saw that on the fronts. I guess the big question is how much worse are they wearing than the rest of the tire?

Whatever you do, do n't underinflate them, that's just asking for trouble.

I agree. Underinflation is more of an issue, and will actually cause more stress on the sidewall. 35psi cold.

By "cold", just check the tires in the morning before they have been driven on and before they are in the sun.

I had a lady come into a gas station that I worked at years ago. She wanted me to check her tires. Her grandson had filled them up until they "looked good". 50 pounds front, 70 pound rear. Don't do that :icon14:

:icon18: Yup.

Most drivers are lazy about maintaining proper tire pressure. They ignore this, and often run at low pressures. As DavesZ#3 mentions, this is a very bad thing.

But then again, some people decide to maintain the pressure. They read the maximum pressure on the tire’s sidewall (maybe something like 50 psi), and jack-up the psi to that value. :eek:

--Spike

What are the proper tire psi's for hpde on stock 18 touring sizes?

Im not lowered, but I do have sways installed.

Depends on the tire. I would start at stock and work around to see how it feels.

^^ Great answer!

--Spike

Bridgestone Re070's in the rear and Dunlops up front. 35 psi cold?

I would assume tire manufacturers expect an increase in pressure at high speed or high temperature conditions and build the tires to handle the change. Decreasing the at rest tire pressure will increase tire wear and may have a negative effect on handling. I live in Arizona and summer temperatures in the 100s are not uncommon. Under highway driving tire pressure is usually at 40 to 42 psi. Never had a problem with my Bridgestone factory tires or the Michelins I have on the car right now.

I recently saw a post where people would have up to 40psi in a tire for hpde's. Sounds very high to me. I wouldn't want mine that high but its personnal preferance for track.