Tires: Tire inflation, proper tire inflation, gmc z71

Question
Hi Barry, my question is about proper tire inflation. I have 285-75-16's on my GMC Z71. Not factory equipment of course so I'm stumped on proper inflation for my vehicle. The max psi on the sidewall is 65psi. I've been running around 50 and about 40 if going off road. Almost time for some new treads but I'll prolly still go with 285's, that is till I lift my truck a lil bit. Thanks. Chad H.

Answer
Chris,

There is some information that is needed to answer your question - and the quick way to get it is for you to look at your vehicle placard - which will be located on the driver's doorpost.

What is needed is the original tire size and the inflation pressure for that size.

The one other thing that is needed is the tire size that is on your truck now.  Is it a "P" or an "LT".  This is important because they work differently and the pressure requirements would then be different.  (BTW, I already figured out they are "LT" because of the pressure, so this is just a reminder to include that information in the future.)