ericnottelin

Unfortunately, the EPA doesn't require testing on HD trucks. So the manufacturer doesn't test it for mileage. The best you are going to get is personal statements. Unless a magazine did a test prior to doing an upgrade. Sorry

bails

Thanks for your input...can't find much on that forum...and the registration is taking forever.

ericnottelin

Figures.

From what I am reading, guys are getting anywhere from 8-12 mpg towing (depends greatly on trailer weight, speed, and trailer design). No city numbers. Hwy varies greatly with your speed. Guys seem to be getting around 18-20 at 60-65 mph. Anything over that and they guys are saying mpgs go down fast.

That would be consistent with 3.73 rear end gears. That gear ratio is designed for towing and not highway mpgs. Going faster than 65 would definitely put you into higher revs which in turn would eat more gas.

My 1500 has the 3.73 and I am in the same boat. Anything over 65 and my mpgs go way down.

Don't know what you intend on using it for. I am assuming that you are towing with the dually and 3500 diesel. So speed wouldn't be an issue anyway. But when unloaded, the faster you go the more revs you have and the more go go juice you drink.

bails

Thanks...yeah, I have a 33 foot travel trailer that was asking too much from my 1500HD.
I'm only getting 13.0 with the 6.0L gasser...

08chevy262

If I were you I would not get a one ton dully. You would be better off with a 3/4 ton. We pull our 38' fifth wheel which weighs 14,000lbs dry weight and our truck barley squats. Its an 07.5 (new body style) with the Duramax 6.6 with the allison. 3.73 rear end 4x4 crew cab short box. Truck doesn't even work pulling it when its loaded. And we get around 14mpg on the hwy at 70.

ericnottelin

Thanks for jumping in guys! I really didn't have much to go off of since mine is a 1/2 ton 4.8l