Pickup - Different Front/Rear Inflation PSI?

[TWG1572]

Hello -

So, I have a new set of General AT2's on my truck. Put about 600 miles so far on them, first impression is very positive. Ride/driving quality is much better than the stock BFG Radial Long Trails. Hopefully, I've got the same opinion 50K miles from now.

Anyway, the weight distribution on my Frontier is 56% front 44% back. Door sticker says 35PSI all the way around. I kept my BFG's inflated properly, rotated, and got 55K out of them - not bad but you could tell that the middle was wearing quicker when they were on the back.

I'm guessing this is typical with most trucks. I know what the door sticker says, but have people had any luck with running a couple PSI lower in the rear to try and get better wear? I have yet to try the chalk test on the tread to see what it says....

Thanks!

 

[justinf89]

If I were you, I would calculate the psi based on your weight distribution findings. In my silverado, I run 55 in the front, and 45 in the back, unloaded of course. When I tow or haul, of course I'll bump it up a bit. I run lower rear pressure in all my vehicles, but it's especially important in the pickup. The way I found my pressures was simply trial and error. I don't know the weight bias but 55/45 gets me perfect tire wear to the outer edges.

Edit: MY door sticker says 55 front, 80 rear, which would be completely loaded I assume. I know some people that run this all the time and their tires wear like garbage.

 

[SteveSRT8]

In my Silverado I also stagger the pressures quite a bit from front to rear, with the rear being lower if the truck is unloaded.

 

[Colt45ws]

I would assume they are specing it with maximum loading in mind. A little bit under would probably be fine.
Ive noticed recent Dodge pickups are actually coming with a sticker that specifies a "unloaded" pressure and a "loaded" pressure. The unloaded spec is as you would expect lower out back than up front.
How they work this in with TPMS I don't know.

 

[Ramblin Fever]

My cummins diesel specifies 65psi front, 80psi rear - loaded, which IS what I run when I'm loaded with 5th wheel, etc.

When I run empty, I run 60psi front, and 50-55psi rear - the diesel is a heavy engine, which could account for the psi requirement in the front end.

My 97 rodeo literally states on the door label to run 29psi front/32psi rear....however my tires would always feel squishy and wear out fairly quick until I started running 35psi front/37psi rear, now I get fantastic wear out of the tires and the cornering, etc is much improved.

 

[cafasco]

The chalk test is the way to go for conclusive results. Otherwise I would run 35 in the front and 28 to 30 in the rear. You will have less oversteer as well (handle a bit better). Bump the rear up as you add weight.

I ran 45 front and 30 rear in my 96 dodge ram 4wd empty (otherwise suffer major premature tire wear in the centers). There was A LOT of WEIGHT up front! I would bump the rears up to 45 when fully loaded.

My buddy ran his chevy 4wd tires at max pressure all the time. I could hardly stand riding in it. He was saving a nickel in gas and losing a buck in tire wear.

 

[CapriRacer]

Originally Posted By: cafasco
The chalk test is the way to go for conclusive results........


I am not a fan of this method, because it assumes that if a tire is properly inflated, it will give even wear - and that's far from the truth.

Tire wear is extremely complex. An example of this is that steer tires tend to wear the shoulders and drive tires tend to wear in the center. That in and of itself says that the method is prone to false results.

Besides, I know that OE tire engineers (the ones designing tires to meet the vehicle manufacturer's specs) will compromise the wear in order to get rolling resistance - and one of the common techniques is to sacrifice the wear in the shoulders - making one conclude the tires are under-inflated.

 

[Colt45ws]

They use a different (faster wearing) compound on the shoulder? Or are they designing it in a way as to cause poor wear there in order to improve RR? When I see that, tires worn through on the shoulders, it does make me assume long term slight under inflation.

 

[Gene K]

Ive found on half tons I usually get the longest life out of the P rated tires by running max sidewall pressure. They will still wear toward the outside in the front and centers in the rear but it equalizes with rotation. Now on LT rated tires this might have to be changed.

In my new Dodge the door sticker says 40 psi / 40 psi and sidewall rating is 44 psi so really not much difference.