Inflation Pressure
 

I have BFG A/T on my truck, size 315 75 R16. The tire side wall say to inflate to 50PSI max, but the door pillar on the truck says 80 Rear, and 65 front.

Who are you supposed to go by? I have always been told to go by the door, but BFG set there limit at 50.

What is your opinion?

This isnt an opinion.

80 psi is for E rated tires that came on the truck. I suspect your BFG is a D rated tire.

With a 50 psi max I'd be almost sure they are C rated tires, every D I have seen calls for 65 max. I hope if you're runnin C's you don't haul much.:c:

C rated tires even on an empty 3/4 ton would be dangerous IMHO.

I always called a tire store that carried the brand and went by their recommendation. When I had load range E tires on my half ton, they were WAY more than what I needed, buy wore way better. Minimum pressure they suggested was 42 PSI, so I set it at that to try and get a good ride. They needed 50 to wear properly, and I was able to find that out in 5k KMS, or 3000 miles APROX.

I dont know off hand what the load range on a c is, but it's probably fine without a load. My half ton gasser came from the factory with P series tires on it and that was a crew cab. :c:

Now I am irked.....

I told the tire store I needed E rated tires no ifs ands or buts

Looks like doctor evil is right I went to the site, the load range is 121 whatever that means, but they are listed as LT315/75R16/D

My "E" rated tires call for 65 psi... Toyo Open Country M/T :humm:

I have no idea what the 121 stands for either but BFG A/T's come in both D and E rated flavors. Do you tow heavy? If not, i think youll be just fine with the D's

Any of the E rated tires Ive had have been good to 80 psi. I have no idea either why the Toyos would only be good for 65 psi. Maybe Tireman does?

My Kelly's are D rated with a max psi of 50. I just set them at 50 and drive it. If I need to air up a bit when I have a heavy load, I do but then I keep it below 60 mph.

Must be the larger size D's take less air pressure, my 285/75R16's in a D call for 65 and every E rated tire I ever looked at call for 80 psi, I've never had Toyo's though, or 20'' tires :c:

I would only go by what the door says if you are running [B]exactly[B] what came on the vehicle from the factory. It makes absolutely no sense to me what so ever to go by the recomendations for one tire when you are running something completely different. I go by what the sidewall says. I had a set of D rated tires on my truck that called for 65 max, and just put on a set of E's that list the same max of 65. As far as I can tell, the only thing that the letter stands for is the number of plies the tire has. I have seen D's that have a higher actual rating in pounds than some E's. There, my rant:argh:

Actually the PSI on the sidewall is the max possible psi for that tire and you're supposed to go with the inflation pressure recomended by the vehicle manufacturer. Of course that means for the same load range tire specified on the door tag.:c:

I figured that post would spark a little controversy:w2: I guess I should have said that I usually run my tires around 50psi, unless I'm doing alot of towing then I will bump them up to the max. But if I had a tire with a max of 50, I'd probably go with around 40-45.

I wonder how you guys get a tire shop to install D rated tires on your truck, I've asked several tires shops and they all tell me the same thing they are not allowed to sell and install a D tire on any vehicle that came from the factory with E rated tires.