265/75-16 load range C tire pressure

A month or so ago I bought a set of 265/75-16 load range C Goodyear Duratracs for my close to stock weight '11 DCSB. When I asked the guy how much pressure they put in them he said 40 psi. Today I finally got around to checking their work (yea, I know it should have been done that day). First I checked the torque and that was right where it should be. Then I chalk tested them and it looked like they were just a bit overinflated. But the pair of POS gauges in my glove box wouldn't agree on a pressure. Bought a quality dial type gauge and they all read between 32 and 33 psi. Tread depth measures slightly less on the center lugs so that was a hint that the pressure should be a lot lower than I thought. So I aired them all up to 35 and took a drive. 35 feels good but the chalk test leaves about an inch of residue on the inside and outside lugs. So down to 33 on all four corners and still too much residue on the outside lugs. In the end I went down to 31 on all corners and the front is reasonably close but the rears need to come down a bit more. At that point I ran out of time so will run this way for a few days and see how it goes. More to follow when I get them dialed in for maximum wear with a report on ride quality.

 

I ran the same tires 4+ years, I ran 32/30 front/rear for years. Then when I got a shell I ran. 32 all four corners. Truck is heavier now so 36psi everywhere, plus I just want really good mpg while I run them until I get new tires in a few months.

 

Thanks Crom. Im guessing that is going to be 28 or 29 rear and 30 or 31 front for maximum wear/longevity which surprises me. Wish all these TW opinions about tire pressure would document weight above stock, load range, and if they ever tried chalk. Opinions, educated and otherwise, all over the place with very few facts.

 

Test (sorry, have a dupe thread floating it there).