Just bought a set of Cooper Discovery AT3's. After I got home I thought they looked a little soft. I checked the PSI and they were all at 35. This after drving at highway speeds for a couple hours. I thought that was a little low for an E rated tire. I have run E rated before and never had them lower then 45psi. I called Discount Tire where I just bought them and the salesman told me that the truck called for 35psi and it doesn't matter what the rating is. This dosen't sound right to me. Any opinions?

 

35 psi may be for the stock P rated tires. I would never go below 40 psi cold in a E rated tire and that's for an empty truck for everyday driving.

 

Had similar question, I was thinking that the #'s on the door were only applicable to the P rated tires as well.

I keep mine at 42-45 front 40-42 rear.