Ok fellows. I have been lurking around this forum for a few months now so I am not a newby even though this is my first post. I bought an 05 F350 crew cab long box diesel back in July. I have the cheap stock tires on it and when I got it of course it had 70 psi in the tires. Now that summer if over I am not hauling or pulling anything the 70 psi just seems a bit too much. I dropped it to 46 psi about a week ago and the ride is much smoother and tires still seem to be holding their shape (ie they dont look low or flat).

Just curious as what most of you use when you are not hauling/towing etc. I cannot find any recommendations about psi when not loaded. The tires just say 70 psi.

Thanks

 

I am running BFG'S 315/70/17 AT 40lbs Front 35lbs Rear I been running this set up for about 10000 miles so far the ride much better and tire wear fair.

I now runing AMSOIL I seem to be getting better MPG I picked up 1 to 1.5 MPG more on the HWY.

2002 F250 4X4 Reg cab, 5.4, 4.56 gears, 6.5 Pro Comp, Blistein shocks.

 

running what is listed on the truck tag on drivers door.

 

I run my 18" Conti's at 65psi just like the sticker on the door says. I've run them at 55 and while the ride is better, the mpg's dropped just a little and I think tire wear on the outside edge would be worse at that. I have 26,000 miles and the tires look like new.

 

Just do the chalk thing. Scribe a line across the tires then drive a few feet and see where the chalk is left, as an indication of how much of the tire is hitting the ground and where.

This is pretty much the first time I've seen people admitting that they sometimes run pressures in the 40's. Take that pressure, and pretend for a moment you have 4 tires on your rear axle and not two..... I'm actually running 25 psi on my rear tires, and they still don't completely touch the ground!

 

By the way, my tires are rated for something over 80 psi. At that pressure only the center tread (at the rear) hits the road, so it I don't buy it.

 

BareBones... do you have a dually? 25 psi in each tire on a dually is probably about right for running around empty.

I previously had a F150 shortbox regular cab. This thing weighed nothing in the back and I had to watch the pressure in the tires. If I put too much air in and ran a lot of miles on the highway the tires in the rear would wear very unevenly. That is they would wear in the center really bad and I think it was do to not enough weight in the back, and I am guessing that the centrifigal force of the tire running at 75-80 mph would make it bluge out even more in the center of the tire contributing to the uneven wear. At least that was my theory because I had gone through 2 sets of tires before I began putting less air in them and as a result saw less wear.

 

I usually run 50 in the rear during the winter. When I ran 65, I felt like I lost tracktion in the snow. Fifty seemed to feel just about right.

 

something over 80. What kind of tire are you running. A E rated tire is rated at a max pressure of 80. That is a 10 ply tire.

anyways I would recomend 55 when not towing anything. you could bump it up to 60, maybe even 65 if you want, but I would say 55 will do you good.

 

The E tire on mine is stock, a Firestone Steelex R4S in 265/16. It LISTS a max load of 80 lbs at 3415 lbs. When I picked it up from the dealer it had 85 in it, front and rear.
I run them at 65 with no load, 75 with a full load of dirt in the bed.
My tread wear is even across all four tires.
Fuel economy is great at this pressure, but I'm going to bring the rears down 10 lbs for a smoother ride.

 

I used to run my Steeltexes at about 40 psi for ride comfort, then air up to 50/70 (front/rear) when hauling a load. These wore evenly.

I put new Bridgestone Revos on and had an alignment doen. The alignment guy (highly respected) said to run higher pressures in front (55-60?) to have uniform front tire wear. He said the more aggressive treads, like on the Revos, would wear unevenly if the pressure was too low.

Fortunately I have Rancho 9000 shocks so I can lower the pressure to smooth the ride somewhat.

 

Right. They're E's. 3200 pounds at 80 psi for SRW, 2900 at 80 psi for DRW.