I have 2001 f250 SD 4wd front tire seems a little low looking at the plate on the inside drivers door says tire pressure shound be front 31 lbs and rear 48 lbs am i reading this right???? Tires are lt265/75 16 what do you guys have in yours?Thanks

 

I'm not the sharpest tool in the shed, so I'll likely be laughed at for this but I run my tires at a much higher pressure.

My tires say max pressure is up to 80 psi. I don't go that high, but I keep all 6 at about 65 psi.

The ride is fine and I get a little bit better MPG

 

The stock answer is to check the pressure label on the door jamb, but this label is assuming factory tires and a truck loaded to the GAWR’s (Gross Axle Weight Rating). If you are operating at a lower weight, you can reduce the pressure for better tire wear, smoother ride and better traction.

Here’s the proper way to determine what pressure to run in your tires. Weigh your truck, getting individual weights for each wheel (or at a minimum each axle). Then consult the tire inflation chart for your brand/model of tire. You can view a chart at: http://www.trucktires.com/bridgeston...V_Brochure.pdf . The chart will tell you what pressure to run based on your weight. If you got individual wheel weights, use the heaviest wheel on an axle to determine what pressure to run on all tires on that axle. If you weigh your truck unloaded you’ll need to do this again with your normal load. If your load fluctuates all the time, it’s probably easier to just keep the tires inflated to handle the highest load you anticipate.

In my case, I carry a 4000 lb slide-in camper occasionally. I keep the truck tires inflated for unloaded driving most of the time. Then before I load the camper, I pump them up for the extra weight. That way the truck rides smoothly with good traction and even tread wear while unloaded. If I was loading and unloading the camper daily or even weekly, I’d probably just keep the tires pumped up. Changing tire pressure daily on a dually would get old real quick.
It's a good idea to read the footnotes and fine print in tire inflation manuals also. For instance, in the Firestone manual it says that if you are driving for long periods at 65 to 74 mph , you should increase the tire pressure 10 psi (provided the wheels are rated to handle the pressure). In the case of the Firestone Steeltex 265/75-16 tire that would be 90 psi if you are at max load. This means that the 80 psi listed on the sidewall is not the max pressure. If you want to drive 75 to 84 mph , you still need those extra 10 psi, but you also need to reduce you max weight capacity by 10%.

As an example, here’s the inflation table for the LT265/75R16 Firestone Steeltex tire (or other brands in that exact size)

Weight Pressure
1910 35
2100 40
2280 45
2470 50
2625 55
2790 60
3000 65
3105 70
3260 75
3415 80

65-74mph add 10psi
75-84mph add 10psi & decrease load 10%

 

DO the chalk test for YOUR tire pressure on YOUR truck with YOUR conditions....

 

I'll second that; this method has served me well. To elaborate, since it's not pointed out in this thread, get some big fat chalk, and then find a nice stretch of really smooth pavement. Draw a chalk line across the face of the tread, and then roll forward a few revolutions to see how it wears off.

If it wears on the edges, put a little more air in the tire. If it wears on the middle of the tread, let some air out. Keep working on it until you get the chalk to wear off evenly across the whole tread, and then note the pressure.

I did this on the 33" Mud Terrains on my FJ40, and on the 35" All Terrains on my '69 GMC longbed. In both cases I have gotten really even wear from the tires, which are at about half of their lifespan on both vehicles.

 

I run 60 frt 60 rear on my '99 F-250 SD SC V-10 short box empty with 265's

 

Check the load range of the tires you are running. The D's max at 65psi whereas the E's max is at 85 psi I think. I keep mine all at 65 psi too.