Tire Size Change Question

[Jackpine]

Originally Posted by stryker6040

Thanks for the info. i have never heard of the squish until you just brought it up but i guess it does make sense. Another thing I was wondering is what should I run in these for air pressure? I currently have 35psi in them they are procomp xtreme mt in lt315/70r17 i was debating putting 40psi in them but i dunno

Grabber gave you a good answer, I'd call Procomp too. Somewhere, on the tire's sidewall is a max pressure value. DO NOT exceed this! And, I'm sure you know to check your pressure when the tires are cold, not after being "rolled on" for a while.

Just as a "guess", I suspect 35 psi is way too low. The OEM tires I had on my truck were recommended to be at 40 psi. At the recommended pressure, you maximize load carrying ability and treadwear, and minimize rolling resistance, heating (due to sidewall flexing) and hydroplaning on wet roads. If you over inflate, you tend to wear out the center of the tire tread and you increase stress on the entire tire and wheel which can lead to blowout.

I think, at the correct pressure, the squish value I gave you will be just about right. I was actually coming up with a 6% correction given your speeds, and that tells me you are underinflated too.

- Jack