Tires: Tire pressure, P to LT, oem tires, tirers

Question
I read many of your other answers, including not switching from P to LT. But the deed has already been done--my dad told me LT's were "tougher". I have a 2003 Chevy Silverado K1500 extended cab/short bed (Z71 if that matters). I replaced my OEM tires (Bridgestone Dueler A/T P265/75/R16) with Goodyear Tracker 2 LT265/75/R16 (C load range with a max load of 2470 lbs at 50 psi). The tire guys (Walmart) filled them to 35psi as the placard says for the OEM tires. I've driven them about 250 miles with no extra payload and have not noticed a handling change, however in a few weeks we'll be moving from Oklahoma to California and loading it and a Uhaul trailer about 1000 lbs from GCWR. What pressure should I normally run these tires at (empty payload) and should I increase/decrease this for heavy weight applications?

Thanks for the site and advice,
Stephen

Answer
Stephen,

Lt tires require more pressure to carry the same load.

The original P265/75R16's at 35 psi are rated at 2601 #, but because they are "P"'s used in an "LT" application, they have to be derated 10% to 2365 #.

For an LT to carry 2365 the pressure has to be 48 psi!  And that's only one reason not to interchange the 2 types.

The other reason is when you slam on the brakes, the rear shocks think you have a lower spring rate and with the stiffer tirers you might develop wheel hop.  If you've ever experienced wheel hop under braking, it will scare the daylights out of you.

Normal practice is to use the placard pressure for all usage.  So normal practice ought to be to use 48 psi regardless of the load.

(But I think you can get away with 35 psi when it is empty, but I sure don't like saying that.  People forget!)