Duramax gas mileage

[Pyrotechnic]

What kind of gas mileage are people with Duramax's getting ? Since they came out i've been wondering but I know they aren't required to post mileage figures for them. Also, please post the size of the truck (reg cab, crew cab, extended cab, short bed, long bed) and 2500 or 3500 and auto or manual.

[northerngmc]

I have an 04 2500HD,Crew Cab, 4X4, regular box (6.5ft), duramax with the allison auto and the Edge EZ power module (which I leave set on #1, which Edge claims is the 'mileage' setting).

I am in Canada, so I am using imperial gallons, but in the summer driving 75 mph down the highway on a long trip I will get 21-22 mpg (18-19 in US gallon).

There is a big difference between summer and winter diesel so my winter fuel mileage drops 10% or more.

Last summer I towed my 31 ft travel trailer from Edmonton AB to Vancouver BC, which is over/through the mountains. Pulling the trailer I go slower, maybe 60 mph, and I was able to get 16 mpg.

The power is wonderful and the mileage is a real bonus. Just to compare, my brother had a 04 2500, extended cab, long box, 4X4 with the 6.0 gas engine. Simliar highway conditions and he would get 14 mpg to my 21 mpg.

But you can buy a lot of gas for the $10,000 price tag of the duramax/allison.

[1lowdiesel]

i've got an 05 and i get around 17 or 18 if i drive it normally. i have an edge juice, bully dog pup, boost controller, egr delete, and a few other odds and ends

[vtblazer]

I got an 01 last Sept. and will never go back to gas for my work/hauling vehicles.
It's an extra cab w/6ft bed, D-Max/Ally combo. The Allison is amazing.
Average fuel mileage is 16/17 around town loaded with my tools etc.
(about 500/600lbs)

We travel to go wheeling so I tow about 8K/9K when we go.

One trip I used a buddy's 05 Dodge 3/4 ton w/a 360-auto and averaged 7.5 mile per gallon round trip.
It was working hard to maintain 65mph.
The truck itself hauled the load really well but having to take some of the grades at 35/40mph just wasn't okay.

Next trip, same destination (400 miles each way), I had my D-Max and got 13+ round trip traveling @ 75/80 and never under 65 even on the grades.
My buddy was driving his 8.1 w/Ally and got about 6mpg.
He could keep up for sure but paid the price for it at the pumps.

I've done one other long haul trip pulling around and delivering 67-72 trucks and got almost 18mpg with the lighter load and more conservative speeds.

Watch the winter diesel, use additive and you'll be all set.
I found out the hard way trusting that the station's fuel was prep'd for cold weather.

I've had a new 01 HD w/6.0 and a 02 1/2 ton Z-71 and really like these years, so getting into this 01 D-Max was perfect for me and my uses.

[62 short step]

I don't have the duramax, but my 07 classic 2500hd wih the 6.0 gets about 16-17 on the highway. In town towing my 7 x 14 enclosed trailer I get about 10-12. But I have a very heavy foot!!

[bad_turbo]

I've got an '01, '02 3500 and an '03 4500. All with the Duramax/Allison combo. They all pull 3 car trailers that are either 48 ft or 53 ft long and weigh 7k empty. The heaviest load I have carried was 3 late model suburbans on my 53 foot trailer being pulled by the 4500. They all average 10-12 mpg with the trailers on. All of these trucks have about 300k miles on them now.

[Pyrotechnic]

That C4500 is sweet. I heard those have an extremely good turning radius