[540Cummins]

I have 285/70/17 nitto terra grapplers on my stock wheels...Just wondering what tire pressures I should be running...Bought the truck used and the original owner put the tires on and had the dealership reprogram the tpms and currently the tires are 76lbs. all the way around...but to me the truck is a little rough riding (stock suspension) and was just wondering with less pressure if the ride would become better...any info on this would be appreciated...thanx

 

[NorCaler]

I have 285/70/17 nitto terra grapplers on my stock wheels...Just wondering what tire pressures I should be running...Bought the truck used and the original owner put the tires on and had the dealership reprogram the tpms and currently the tires are 76lbs. all the way around...but to me the truck is a little rough riding (stock suspension) and was just wondering with less pressure if the ride would become better...any info on this would be appreciated...thanx

55-60 front
45-50 rear

If you want to get real picky drive the truck on the freeway for 5 minutes at a time, pull over and check tire surfaces with a digital pyrometer. Keep lowering tire pressures until you see the same temperature across the entire tire surface. You will have to do at least 4-5 sessions at 5 minutes each to get it dialed in. As an example: the center of tire could read 125 degrees, the outboard tread surface could read 125 degrees and the inboard edge of tire surface could read 125 degrees. The temp doesn't matter, just make sure the temps are all the same.

At your current tire pressure I can promise you your tires are running hotter in the center when compared to the edges. Adjusting tire pressure as stated above will give you even tread wear when done in conjunction with tire rotations.

 

[john2669]

Front 75
Rear 60

This makes those tires wear pretty good

 

[Flattman]

55-60 front
45-50 rear

^^^ perfect for unloaded, cold PSI. In case you're interested I have about the same size in 18 inch and run max 80 PSI in the rear and 75 PSI in the front when I tow my 5th wheel (heavy).

 

[NorCaler]

Ya I guess I should have clarified that was unloaded tire pressures. I just assumed that was what he was asking for was unloaded. :confused013:

 

[gotdiesel04]

Granted my previous truck was a 3rd gen 2500, but Norcaler's pressures are right on the money for unloaded. I was running 285/70-17 Toyo AT.

His advice for finding the ideal pressure for your truck works well, also. I used to use chalk across the tread and drove until it wore off evenly......OCD, I know, I know.....lol

Loaded hauling my 5er....70 frt 80 rear