I have a 2004 PSD with 35" BFG AT's (6" lift from Tag Motorsports) and the sidewall rating says 50 psi max I believe but the door psi rating says 60/70 max.

The tires are at 35 psi right now and am wondering if I should be at 50 or more instead?

 

with a bigger tire like that you only really need to put the max psi in them if you are loaded down. what will happen is they will start to wear in the middle of the tire

 

Do not put more air in the tire than is listed on the sidewall. The sticker on the door is for the tires that came with the truck from the Ford plant.

 

Sorry for appearing as though I am an idiot... but I was in a hurry and wanted to make it simple. I know I should not go over the rated sidewall numbers and that the door pillar marking is for the tires that shipped with the truck...

The real question if you all had been true mind readers - would be that I am at 30psi and would like to go higher as I am trying to up my gas mileage. Would it be benifical to do so?

Yes, I watch for abnormal wear patterns such as too high (middle) and too low (outside).

 

Air pressure at sidewall pressure rating will give you the best MPG on any tire.

But at some point the MPG increase will be offset by lower tire life.

 

to give you a "for instance" i run 285/75-16's on the stock rims to gat even tire wear i run 45 psi front and 40psi rear unloaded. max on the side wall is 65psi. i want the tires to wear evenly and am not worried about what ever the milage difference may be.