Tire Pressure - What should it be..really?

[One-Bad-ZL1]

I searched but have not found the answer to this question....

The Pirelli P-Zero's sidewall states a max pressure of 50 PSI, the car's tag says 36 PSI, it appears the TPMS goes off at under 32 PSI...I was always taught not to follow the tag cuz you never know if the tires have been changed from manufacture's specs...so I've always adheared to the sidewall. Is everyone else doing so? Not looking to wear these out in 15K.

It would seem GM set the low pressure warning for these tires too low, if that is the case. Cold, they should hold about 45 PSI and will warm up close to max. Logical right? Can we set the TPMS to alert for higher pressures, say 40PSI closer to the tires actually rating?

OK, let's hear it. Thanks.

[90503]

I go with the 36 cold off my own tire gauge...the dash reading has never matched yet!

[bradshaw]

36 is correct, always follow the cars recommendation for proper handling.

[rberns]

Are you sure the side walls say 50psi? Before garaging my camaro I thought it said Max 44psi.

[90503]

Originally Posted by rberns

Are you sure the side walls say 50psi? Before garaging my camaro I thought it said Max 44psi.

I always thought the "max psi" was only needed if you were at the very top of the vehicle's loaded gvw....not really applicable to passenger cars...

[bajamoon]

I keep mine at 35-36 cold. I have to put air in once a month or so.

[The_cartoonist_88]

I keep mine at 36. Always go with the vehicle recommendations

[lewylew]

I keep mine between 36-39 psi. When I went on SRT driving experience they kept the tires on the SRT vehicle, on roadcourse at 50 psi. Thought that was a little high, but the cars handled really good.

[Parag]

the max psi is for setting the bead. for stock size always go with the body tag. but if you put 22's on, you want to adjust accordingly

[mulletman]

50 PSI is not the recommended tire pressure. 36 PSI cold is what you should be running.

[mmarx82]

Originally Posted by bradshaw

36 is correct, always follow the cars recommendation for proper handling.

Originally Posted by The_cartoonist_88

I keep mine at 36. Always go with the vehicle recommendations

These...

[Avalnch]

Originally Posted by One-Bad-SS

I searched but have not found the answer to this question....

The Pirelli P-Zero's sidewall states a max pressure of 50 PSI, the car's tag says 36 PSI, it appears the TPMS goes off at under 32 PSI...I was always taught not to follow the tag cuz you never know if the tires have been changed from manufacture's specs...so I've always adheared to the sidewall. Is everyone else doing so? Not looking to wear these out in 15K.

It would seem GM set the low pressure warning for these tires too low, if that is the case. Cold, they should hold about 45 PSI and will warm up close to max. Logical right? Can we set the TPMS to alert for higher pressures, say 40PSI closer to the tires actually rating?

OK, let's hear it. Thanks.

OK, hear this, then. Your logic is not correct. Please DO NOT run your tires near the sidewall max pressure rating. Running 45 or 50 PSI cold pressure can increase your hot pressure way too high and can even be hazardous at worst. Even if your tire doesn't blow on you, running 50 PSI cold pressure will cause the center of the tire tread to bulge out and wear your tires unevenly. Under inflation will do the same to the edges of the tread.

Stick with the door jam recommended setting of 36 PSI. The TPMS low alarm of 32 PSI is probably correct too. A 4 PSI drop in tire pressure from 36 equates to an 11.11% drop which is significant.

[Mr_Draco]

Remember the difference between cold and hot pressure is about 5 PSI during the summer and more than that during the winter.

During the summer i run between 35-40 PSI cold depending on if I get distracted for a few seconds while putting air in.

During winter I run a little bit less cause the air will expand more when the tires warm up. I run about 30-32 PSI cold during the winter.

[suplex]

Originally Posted by Mr_Draco

Remember the difference between cold and hot pressure is about 5 PSI during the summer and more than that during the winter.

I had always thought it was 1 PSI for every 10 degrees temperature difference. However, if that's true, what do they consider the "starting" temperature?

Let's say they refer to 70 degrees as the initial temperature, and your car is supposed to be at 35 PSI when it's 70. I would assume that means that if it's 40 degrees out, you should set your tires to 38 PSI, and if it were 100 degrees out, then set the tires to 32 PSI. So if it's hotter out the PSI goes down, and if it's colder out the PSI goes up.

Am I correct according to my above example?