For what its worth, this is for a GMC 2500HD, Duramax.  But I don't think that matters as much as the door sticker readings included below....

Ok.....
All measurements below are "cold" readings, ie the truck has been sitting for at least three hours.

The door sticker in my new truck for tire pressure says:

Front: 60 psi
Rear: 72 psi

The dealer had them set at:
Front: 55 psi
Rear: 62 psi

I think their reasoning is that when you drive it it "feels" better with less air in the tires .

Now, I am not willing to go below the minimum pressures (per my door sticker).

My tires themselves are rated max 85 psi.

What psi should I be running them at normally?

What psi should I be running them at for towing?

My father seems to think (and he is pretty smart) that I should run them at:
Front: 70 psi
Rear: 75 psi
For towing, and non-towing driving.... he also thinks I should ask here.... :)

What do you guys think???

My answer will certainly stir up a bit of a mess..... When I have my truck set up during the summer for heavy work, carrying and hauling, I set my tire pressures to the maximum stated by the tire manufacturer that I use. In my case they are "E" range tires and I use 80 psi. I have a single rear axle tire, but if I had a dually, the rear tire pressures would be lowered to the 75 psi stated on the sidewall.

During the winter when my show and work season is curtailed for several months, I lower the tire pressures to 65 psi. On my trailers, I only use the maximum pressure.

Many people will argue that the best and only pressure to use is what is stated on the door tag. My opinion is that this figure is not representative of a maximum load condition, and does not allow the tires to carry the total weight that the tire manufacturer has designed. The tag numbers indicate an average pressure in which an average load and reasonable ride is achieved.

When I pull a LQ trailer, three horses and my family, I want the most capacity I can get from my equipment. This is not possible using reduced tire pressures. Reducing tire pressures will result in increased heat under loads. This leads to increased tire carcass failures.

I don't have an issue with increased center tire wear, because my truck is only used for work and is not a daily driver. The result is that I don't drive around at a max tire inflation with an empty load. Off season the lower pressures offer a uniform tire wear.

Your tag can be used to get a ball park, best all around pressure. I think after the Ford debacle, the manufacturers are a little less concerned about ride quality and are more in tune with selling the load and towing capabilities of their trucks.

BOL  Gard

If you run your tires at a maximum pressure when you are driving unloaded, the thread in the center of the tire will wear faster than the thread on the edges. When you are not carrying heavy weights, you should use a lower tire pressure. This usually is the pressure listed on your door tag.

BOL  Gard

Gotcha, thanks!

So I run it at the door sticker, until I want to haul, then bump it up.

Glad I have an air compressor at home!!!!  That would be a lot of quarters if I didn't!!!

 Just got back from the tire shop. Six new 215-85R x 16lt lrE, Michelin LTX-M/S's pumped up to 80 psi, front and rear. Truck rides smooth, though it feels a little stiff, it will soften up when it's loaded. Truck stays hitched to a trailer most of the time so I elect to keep them aired to the max. If I didn't tow I would at least keep them at 65 psi front and rear (that's what the door sticker says) for day to day grocery getting. Just my preference.

 Truck is a 2001 Chevrolet 3500 dually.

Ouch.  You must be walkin' tall with that much weight outta your wallet.

I hafta buy eight of them this summer - may try Coopers.

  I done the Cooper thing before, they were cheaper and they lasted about 25,000 miles. Mucho Grande side wall flex with the Cooper Discoverer LT's, but they did ride good!!

 So far as the wallet.....It will be mustard and crackers for dinner, for a while!!!

Yes the sticker psi IS for towing. http://www.goodyeartires.com/faqs/Inflation.html However you CAN fill them to 85 psi if you want, some people "feel" the tires perform better at max, BUT unless you are overloading your axle (per the sticker GAWR) you do not NEED to fill them to 85 psi. The 72 psi will allow the axle to carry the axle rating (6084 pounds?).

Having been to a scale and knowing my actual weights, when towing my 2H BP I run mine at the tire manufacturers recommended 60 psi (front and rear) per the Goodyear load/inflation worksheet, not the door sticker which is for MAX axle loading.

When hauling a heavier trailer (equipment or hay) then I fill the rear to 80 psi as it is hardly time effective to go weigh.  Simply running 80 psi (or sidewall max) all the time, can cause tire damage from impact, WILL reduce tread life, and WILL reduce stopping and stability due to decrease of tire contact patch.