Tire pressures

reb0957 · January 30

I think GM gives some wiggle room based on temp. I saw my recommended pressures were lower than the reprogrammed pressures my truck was set too in myGMC app.

reb0957 · January 30

I think GM gives some wiggle room based on temp. I saw my recommended pressures were lower than the reprogrammed pressures my truck was set too in myGMC app.

reb0957 · January 30

I think GM gives some wiggle room based on temp. I saw my recommended pressures were lower than the reprogrammed pressures my truck was set too in myGMC app.

Jettech1 · January 30

On 1/29/2024 at 12:29 AM, Another JR said:

GM doesn’t actually give us recommendations for how much to reduce pressure at lower weights than the GAWRs, and I suspect they don’t want to take on the liability of providing that advice.

I don’t think GM necessarily “wants” the tire pressure to be higher in the rear when the rear axle weight is way below the front axle weight. I believe the OEM alert pressures for the TPMS are simply some fixed percentage below the maximum tire pressure recommended based on the axle weight rating and whatever handling factors went into setting the maximum pressures on the door jamb sticker. They only want to pay for a fixed alert level, and they want to give you a meaningful alert level for when you are maxed out (probably driven by DOT regulations). Their 80 psi recommendation at 7200 RGAWR and the associated 63 psi alert level (and 70 psi and 55 alert level for the 2500) don’t account for the fact that, when empty, the rear axle weight is only about 3350 lbs.

Towing a medium or heavy trailer is a whole different set of concerns, and you want maximum lateral stiffness to avoid sway regardless of rear axle weight, so “good on ya” JT for running at the max rear pressure when towing.

I pump them up for the reasons you noted when towing. I will say this though, the other day I had a piece of steel ruin one of my tires. 418 to replace it...ouch...lol... And they scratched my wheel that I didn't notice until I got home. I can't win for lose lately buddy. I've got a dark cloud over me that won't go away. Time for an exorcism I think...lol...

Edited January 30 by Jettech1