Well first you must know if they are the 285/65 or 285/55's then you must know if it's a crew max, double cab or regular cab. then if it's a 4x4 or 2x4. if it is a crew max 4x4 then bfg suggests 35 psi front, 40 psi rear for the 285/65/20. this is straight from bfg, if you have something other than that then i suggest you call bfg they have a no crap formula to figure it out. this stops the guessing, if you have any other questions you can pm me. have fun
I keep mine right aroung 45 lbs in my DC RockWarrior. I could probably go a little lower, but I bought a truck and I am okay with it riding like a truck =)! I figure running slightly higher pressure will lower my rolling resistance and help with mileage and lifespan of the tires. Haven't towed anything huge with it yet though.
I checked them today and they were at 40lbs. all the way around so I took them up to 50lbs all the way around it may be all in my head but I think it handles better over rough terrain like rr tracks and rides the same going down the highway I wanna say I also have a 1- 1.5 mpg gain from this on the way to work today but it's very windy today could have a tail wind!
40 was to low 50 was to high in the rear, empty, which is how it mostly is. So somehow I came up with 44 all the way around. I guess airing up for towing and then down is crap, but when you do this 5 or 6 times during riding season, you do have the oppurtunity to experiment a little. The tires are great. I like them in the rain, sand and dry dirt hard pack. Their great on dry roads also. They still look strong when aired down to 12lbs in the soft stuff(sand).