Recommended tire pressure
- Thread starter Wyohab
- Start date
Rovertrader
Supporting Sponsor
highway I would run at or near max recommended inflation, but on the washboards, drop to 32-35 IF you are loaded lightly- more load, more pressure.
ExpoMike
Well-known member
Thought I am running BFG AT's (285/75-16) I am close to the same front and rear axle weight as you. I am running 55 psi all around for street driving and in the dirt. Even on some light washboard trails, I still found the ride better than my Cherokee. I think the weight and longer wheel base helps out a lot. This next trip I am thinking of bumping the pressure down to about 40 psi for the trails, if I end up airing down at all.
Redline
Likes to Drive and Ride
You are running relatively light axel loads there, looks like little to nothing added to the front, Cummins is heavy, and 1,000 lb. or less added to the rear? The answer depends on how fast you want to drive, and how firm/stiff you enjoy the ride. Is that a load range D or E tire in that size? There are numerous variables, and consulting in person is much easier, however...
For that size, in a single rear wheel application, Toyo's inflation charts say:
35 psi 2,210
40 psi 2,430
45 psi 2,640
50 psi 2,835
55 psi 2,955
Technically you would have enough tire capacity with 35 psi in the rears and 40 in the front.
Depending on speed, the conditions, the truck, driver, etc., I would probably run 45-50 in the front and 40 in the rear for highway driving. With the same conditions and cautions I would start at 30 to 25 psi for both front and rear for the washboard. Adjust as needed.
Regcabguy
Oil eater.
I have the same tire and similiar axle loads. These are extremely strong, stiff tires, I'm running 55 psi all around on stock 8" rims. I tried 65 psi for a week,but it's just too stiff. With an 8" rim the 285 wears evenly at 55 psi with my load. My 285-75-17 Toyo AT's wore prematurely down the center with 65# most of there life. Offroad in Utah,I dropped them down to 40# but 35# would have been better. I'm lazy about refilling them although with my Viair,it only tkes 15 minutes to reinflate mine.
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Bella PSD
Explorer
below is dead on to what I was going to say. I ran 285 mud tires on my Ford with the same # and was 45-47 front and 32-35 rear. tires lasted 64,000 miles. Just run chalk on the tire roll forward and check for chalk removal. Adjust until even contact with road. make sure tires are warmed up during chalk test.
Louie
Louie
Buliwyf
Viking with a Hammer
I use the chalk test on the front tires. But I never run less air pressure in the rear than the front. I don't like the way that feels.
For towing I usually increase my fronts 10psi over the chalk test, and max out the rears. Often I go 10% over the max pressure labled on the sidewall.
I also get a knife and heat gun and remove the portion of my door sticker that labels factory tire pressures. That way tire techs are more likely to follow my pressure instructions, but I do try to use the same shop as often as I can so they're used to my specific needs..
For towing I usually increase my fronts 10psi over the chalk test, and max out the rears. Often I go 10% over the max pressure labled on the sidewall.
I also get a knife and heat gun and remove the portion of my door sticker that labels factory tire pressures. That way tire techs are more likely to follow my pressure instructions, but I do try to use the same shop as often as I can so they're used to my specific needs..
ExpoMike
Well-known member
I just returned from a trip where I actually aired down the tires. I dropped them down to 40 psi and ran sand, mud and rocks and everything worked great. I don't think I had any wheel spin anywhere and it gripped ever where. The ride was nice on miles upon miles of washboard roads too. The truck felt stable. I think that 40 psi will be my dirt pressure.