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O.K. on my 97 F350 CC dually the door stickers says 65 psi cold for 215/75/16 size tires.
My front tires are 245/75/16 and the 4 rear ones are 265/75/16.
I didn't put these on there they were there when I bought it and all 6 tires have about 95% tread left, almost brand new. The only thing on the side of the tires I can find says 80 psi but I think that means max. Because they are bigger than what the door sticker is referring to how do I know what air pressure to inflate them to when cold? Also the fronts are two sizes smaller than the rear so do they need different pressure then the rear. I like to keep them at correct pressure for best mph and ride.
There are some load/inflation tables out there somewhere, but I've never seen them. I think you can estimate how much air to put in by comparing the total load capacity of the tire to what your actual weight is. Those 265/15 16's are rated at 3415lbs at the 80 psi, but you likely only have around 3500 lbs on the rear axle when empty, or just 800-900 lbs per tire. You could safely get away with quite a bit less than the 80 psi. If the tire wears evenly, or if the whole tread of the tire is touching the ground, then you have the proper inflation. I bet you can try 65 lbs in the front and 40 lbs in the rear when unloaded, and it will ride better, and see how that does.
I don't know that everyone is willing to change air pressure based on loaded or unloaded, but I do in mine. It rides better and the long term tire wear should be better.
There are some load/inflation tables out there somewhere, but I've never seen them. I think you can estimate how much air to put in by comparing the total load capacity of the tire to what your actual weight is. Those 265/15 16's are rated at 3415lbs at the 80 psi, but you likely only have around 3500 lbs on the rear axle when empty, or just 800-900 lbs per tire. You could safely get away with quite a bit less than the 80 psi. If the tire wears evenly, or if the whole tread of the tire is touching the ground, then you have the proper inflation. I bet you can try 65 lbs in the front and 40 lbs in the rear when unloaded, and it will ride better, and see how that does.
I don't know that everyone is willing to change air pressure based on loaded or unloaded, but I do in mine. It rides better and the long term tire wear should be better.
That sounds like a plan to me. I made a Wally world run and got an extension for my air hose so I can get to the inside rear dual tires. It reaches fine but I still can't get to the stem to get the little cap screwed off. My needle nose pliers are too short, I guess I will have to get some longer and thinner ones from Harbor Freight. The extension only cost $3. I also got a long double sided tire pressure gauge and it reaches back there fine but the pressure reading is not accurate. I compared it with my good guage that goes to 50 psi and it is off about 6-8 pounds. It also was $3 so it's going back to Wally world.
Anyone recommend a good trie guage that will reach through to the rear inside dually tires? I want one that works not one that cost and arm & leg and will win 1st place in a chrome show.
Try NAPA for the tire gauge. That is where I get mine. Tell them that you want the good quality accurate one, not the cheapest one, (double headed for duals) I thing that they run about 8 to 10 bucks. Or you can spend 20 something and get the really long one that's used on semi's. Hope this helps some.
Rockn's advice is pretty good. I normally prefer to consult the tire rather than the door sticker and much of it depends on what you are doing with the truck. hauling heavy go to 80 all the way around. empty you could probably run 65 up front and i would go 50 or 55 in the rear. then you just need to watch your tire wear carefully. More on the edges and not enough pressure, too much wear in the center and you can drop pressure a bit.
definatly go by the door sticker, the engineers put it there for a reason, its definatly good to make sure your tires are capable but if not than you've got the wrong load range tire on your truck and shouldnt be running on them period, a tire with an 80psi max is a load range E which belongs on any truck pulling any kind of weight. i dont think i've ever seen a dually with less than an E, i run D's on mine, and i keep my pressure at 45 all the way around and got 70k out of my last bfg mud terrains, i never rotated them once, they've still got enough tread to pass inspection but i reaplced for new anyway (got pics for nobelivers..lol) i usually dont go overboard towing but do frequently and bump up to 55 or 60 psi and have never had a problem, Mind you they are also 35's.
the easiest way to check your tread contact is either hit a scuff pad (hard to find nowadays) or spin them just a enough to leave a small patch of rubber and see if you have even tread on the pavement.
hahaha, 80psi?!!!! You tryin to burn up dudes tires for him? lol You dont wanna run 80psi in a set of tires loaded down. Leave 'em at 55psi. I run the same tires and this is my third set so far. They are the most happy at 55psi, 60psi @ max.
235/85/16's, I run at 80psi, get best wear and milage out of them on the rear, ride kinda sucks but meh, its a truck, the front I run at 80psi as well but they wear a little funny I've been noticing. In the winter I run at 50psi rear, 65psi front, the tires grab the ice and snow a little better.
The door sticker is psi rating at max load, if you run empty alot you can drop the tire pressures, if you run your tires to low with a heavy load, they heat up alot more on the highway which is not a good thing.
in my experience (disclaimer) with normal street or all terrain tires 265/75/16, running 80psi will call some wear in the center. i recently moved up to some 33 12.50's mud terrains and have been running 55 front and rear. with the trailer or some heavy crap in the bed the rears definitely look a little soft so i do like rockn said and adjust when there is a load. higher psi=lower rolling resistance=better fuel mileage for you hair splitters out there and the opposite for lower psi. 80 is too much unless you got a utility bed full of tools 24/7. oh yeah, almost forgot... IMHO
I thought that only the 235 x 85 x 16's had the 80 psi since their load range is "E". Max Load 3045 at 80 PSI
Cowboy, you would not make any off me.. 235 x 85 x 16's at 80 PSI constantly, 11,500 constant weight, and 30-35,000 miles...When did a 265 get a load range "E". 97 4x4 F-350 C-C 8' bed 5spd and lots of off road work.
I thought that only the 235 x 85 x 16's had the 80 psi since their load range is "E". Max Load 3045 at 80 PSI
Cowboy, you would not make any off me.. 235 x 85 x 16's at 80 PSI constantly, 11,500 constant weight, and 30-35,000 miles...When did a 265 get a load range "E". 97 4x4 F-350 C-C 8' bed 5spd and lots of off road work.