I'm looking at a 96 12V dually xcab and wondering what kind of fuel mileage I can expect with an auto not sure yet wheter it has 4:10 or 3:55 gears? I also am curious as to what the average price for a set of good replacement tires will cost and how much mileage I can expect out of these. I've owned 3 2500's but never a dually.

 

If it has 4.10s, I never could get over 16mpg. (3.55 gears may or may not be much better, mileage wise). Short trip or interstate. After my mods (prior to the 191dv and the flatbed, I was getting 17.5. Lost some with the flatbed. If you get a modded tranny, it will help a little. Won't waste as much on accleration.

I am running Cooper S/T tires. Recently switched to 235-85-16, instead of the stock 215, this time. To early to tell on fuel mileage with them. My last set was also the S/T tires. Was getting 5-6k miles per 1/32" of tread wear. Tread is 18/32" new. Got the last set of 215s for $118/ea. + mnt/bal/valve stems a couple of years ago. Paid $120/ea. this time for the 235s. Mnt/bal/new valve stems extra.

Make sure to get metal valve stems. Not the metal/rubber ones. They tear. Had 2 go, in the first 2 weeks I owned the truck.

 

I should have added the fact that it is also a 4WD.

 

So is mine.

 

If fuel mileage is a great concern stay away from the 4.10.s. I've got over 450k on my 96 3500 and only started getting 15.5-16.5 after going to 255/85 tires.

 

I get 20 unloaded with my dually but it is 2wd and 5 sp 4.10 . I go 60 mph tops and drive easy. towing 10k loaded equipment trailer I get 15 at 60 mph. I can get 16 if I stay at 55.
My guess on 4wd is you lose about 1-2. Faster you lose more.

bentwings

 

My truck doesn't care how fast I drive. It actually likes higher RPMs. Even more so as the engine is setup now. The mileage numbers I posted, were at 70mph. Mileage isn't any better driving slower.

 

Best I have gotten was a bit over 20 MPGs. Last week I got 18.7 on a 460mile run. That included some offroad 4x4 and a bit of blowing some smoke horsing around. Love my truck. Had to pay $3.39 gal to fill her back up. It still smarts to hand over nearly $100 for fuel.

 

DustyRock,
Do you have 3:55 or 4:10 gears in your truck?

 

Mr. Jimmy:

It has 3:55s with the LSD, auto tranny, Goerend Triple TC, amsoil in the Diff.

Dusty