FYI - Tire Pressure Warning on Chevy Truck

[rlhedlund]

Coming home yesterday, my tire pressure warning light came on while tooling down US 64 at 65 mph. I was pulling the Bird and the left rear tire was the one in question. I was not near an exit, so I angled the mirror to visually check it. It looked fine. I had put 80 psi in the rear before leaving home. The light normally comes on when the pressure drops below 60 or 50. I stopped at the next exit and put the air compressor on it and let it run a minute or two while I went hunting for my tire gauge. The pressure was 95 psi. I checked the other rear tire and it was 93.

I did not know the warning light came on for over-inflation??? I bled both tires down to 90 psi. FYI, the air temp was 96 yesterday and the air I bled off the tires was very hot.

After I bled the tire, the warning light went out, so it must have been warning of over-inflation. Did not know that.

[Mike Clay]

My 2008 Chevy had TPI but it never went off with high pressure. Although when its hot I reduce the tire pressure to 75 lbs before i head out.

[Traveler II]

The ONSTAR monthly report tells me to run 71 PSI in the rear and 60 in the front. That's what we've done, what is the correct PSI when towing?

[snoking]

The ONSTAR monthly report tells me to run 71 PSI in the rear and 60 in the front. That's what we've done, what is the correct PSI when towing?

To know the correct air pressure towing will depend on the weight on the rear axle. Then you have to look at the manufacturers tire pressure chart for that size tire for the correct minium pressure. My Dodge had a tire pressure chart with the owners papers. Front of most pickups does not vary much in weight between towing and non towing, so I just run the rear up and down for the load. With 265's rated to 3415 each I do not need a full 80 lbs of inflation with my load. At 70lbs of air, my LT265/75R16E's have the same capacity as LT245/75R16E's at 80 lbs inflation. BTW our Dodge drives like $#+!! without the trailer with the rear tires pumped up to 70-75 for towing. I run 42-44 empty in the rear, and around 57-60 in the front all the time.

Underinflation is really bad for tires, causing excess heat which damages the tire quickly. Overinflation reduces contact patch which can effect braking ability and increase the chance of impact damage to the tire. If one is going to error a bit on inflation, then too much air is better than not enough!!!!

So now for the short answer!

There is not a short answer! You have to weigh the rig loaded, then look at the inflation chart!

Chris

[rlhedlund]

I run 80 in the rear and 60 in the front when towing. Otherwise 65 in the rear and 60 front.

[Mike Clay]

I run 75 lbs for two reasons, one when Im going to be in high altitude and the other when its going to be very hot towing since heat adds air pressure. Truckers let air out when driving in high heat. Around Oregon I run close to 80 lbs in the rear of the truck and on the trailer

[Traveler II]

Thanks for the info.

[Torben]

I have 70# in the front, 80# in the rear, and 80 # in the trailer. And I have the same tires on the trailer that I have on the truck. Michelin LTX, MS.

[Roger]

The factory recommended pressure is for the max load rating of the truck with the factory tires. I leave the front at 60 and air down the back to 55 if I won't be using the FW for a while.

[Chief409]

I check my pressures in the morning before the sun warms the tires up and set them to the recommended pressures, summer or winter. Generally once it starts warming up I will need to let some air out, and add some when it gets cooler. I've never let air out for elevation changes. Even during the summer here in the desert I haven't had tire problems, by rotating every 5000 miles I get 40 - 50000 miles per set of tires (work truck with either B.F. Goodrich All Terrains or Goodyear M&S). And I don't wait until the tread depth gets to 3/16" to get new tires. On the work truck when the tread gets worn and I start seeing rock cuts or even chunks taken out, then it's tire time the next service interval.

Jeff