[oil pan 4]

Originally Posted by lasitter

Generally, larger tires mean lower fuel economy, so replacing my 28.9" standard with the 31 would result in lower mileage. You might think otherwise since the larger tire size acts like a differential reduction, but most everything I've read suggests this.

The mileage stayed the same on my suburban, it may have even trended up a tiny bit. I expected fuel economy to go down by full numbered MPGs. But lucky for me everyone was wrong.
Going to 31 inch load range C tires gave me tires that didn't look like clown car tires and about 1000lb more weight capacity which I do use.
The "hit" to fuel economy was well worth it.

Originally Posted by rmay635703

On my 2wd diesel suburbans I used to always run car tires on the front of the truck and properly load rated tires on the rear (or sometimes car tires all the way around)

I am about to do something like that to mine. I have 30x9.5 inch tires to put up front, replacing the 31x10.5 tires that are on there now.
I only have four 31 inch tires now that one went bad. So instead of buying a new 31 inch tire I got three 30 inch from my friend who bought them and then decided later he didn't want them any more, before he ever even put them on.

On a 2wd diesel suburban the axle weight is very close to 2800 per axle. Make sure the Pmetric tires can handle that much weight after you derate them 9% for being on a tall SUV.