My Ranger never has more than 300 lbs in the bed (muddy dirt bike and gear), and usually it is empty. So I be running less air pressure than the 30psi listed for the rear tires? The reason that I ask is that my rear tires are wearing a little unevenly (more in the middle--you can't really see it, but the tread wear gauge shows it).

 

A bit more information is needed to give you a better idea of what pressure to run. things like; tire size, type of wheels and more details on your Ranger.

 

Tire size is 235/75 15 and the wheels are the stock steel wheels that come with a 99 xlt 2WD. The tires are a little taller than the stock tires that were on the truck. I had to go up to that size to get an all terrain tire. I believe these tires are the same size as what would come on a 99 4wd version of the truck.

Thanks!

 

Whats it say on your door jam? Usually its 32-36 psi. But wear in only the center usually indicates over inflated obviously or a tire too wide for the rim. How are your fronts wearing?

 

Door plate specifies 30 psi. Rims are stock steel. I'm just wondering if 30 psi is too high for (mostly) unloaded running since the rear tires are wearing in the middle (fronts are fine).

My previous truck was a Super Duty that I used to tow a substantial boat on weekends. The door plate specified 80psi in the rear which delivered a ride that would loosen your teeth during the unloaded weekly commute, so I ran 55 psi in the rear when unloaded and added air for weekend towing and hauling.

 

I'm surprised you're getting center wear like that at only 30psi. Is it possible your gauge is off a bit?

 

Yea 30 is not high at all. I have the same size tires and run them at 38 and they wear perfect. Something isnt right here.

 

My gauge is accurate. I'm a motorcycle racer and I monitor accuracy in my gauges.

I'll just try a little bit lower pressure in the back and see how the tread wears through through the fall.

 

You have a couple of factors here.

Yes, tire pressure, but there is also centrifugal force at higher speed driving
If you do alot of freeway driving lower tire pressure may allow more center of tire deflection from centrifugal force, really depends on tire construction.
Where a higher pressure would prevent as much deflection.

Lower tire pressure will always cause more tire wear, more of the tire is touching the road, but it should be even tire wear unless it is too low

 

Interesting! Probably 90% + of my driving mileage is high speed highway driving!

 

I agree. If it is wearing in the center, the pressure is too high even if you ae running 30 psi. I have run street tires at 28 psi before on a Ranger with nothing on/in the bed to get even tire wear. That was on a 4WD Supercab.

 

I think the general consensus here is, the pressure is tire dependent. Like ron said centrifugal force on low pressure on a soft tire, or high pressure on a hard tie. I'm poor so I have cheap hard tires and they run fine at 38... if you have soft tires run less... and vice versa.

 

I think the general consensus here is, the pressure is tire dependent. Like ron said centrifugal force on low pressure on a soft tire, or high pressure on a hard tie. I'm poor so I have cheap hard tires and they run fine at 38... if you have soft tires run less... and vice versa. And rotate unless you have directional tires. There is nothing to adjust in the rear of any ranger for alignment so it's 100% a tire issue.