03 Z71 tire pressure question

[hendedo]

Hello all. Here is our situation.
03 Z71, 5.3L all stock engine & running gear and tire size. Tires are Bridgestone Dueler HT 265/70/17. The door plate says to put in 30 (!!??) psi. We felt that was way too low for the Bridgestones. So, we went to 32. Better, but still a little 'flat looking' to be happy. Also, slight wear difference on the outside and inside edges of the tread.
Now we went to 36 psi on all 4. Much better! Steering is effortless and I bet the gas mileage goes up as well. Tire rating on sidewall says 42 psi is max. Truck is street driven with no trailers etc.
I know pressure is a topic here but why does the door say 30 psi? It really perked up at 36.

Oh, we did the old trick of marking chalk across the tread and driving it to see how it wears off. Seems to be even.
Are we on the right path? What psi are others running?
Thank you.

 

[clkelley]

I test each vehicle independently, to figure out the sweet spot in the pressure. The higher the pressure the higher the risk of wearing the center of the tread out prematurely. This is especially true once the tires heat up on a trip. When the tires heat up the pressure actually builds a little and will cause greater wear on the center tread at highway speeds.

That being said, higher pressures WILL result in a little higher mileage numbers simply due to having less rolling resistance.

It if usually a trade off between better mileage and a little shortened tire life overall. You may not see it as bad without towing anything but with a heavy vehicle tire life will be shortened.