Expectation for Duramax fuel consumption

[DavidJay]

As we approach retirement, I am considering swapping my 6.0 powered Chevy 3/4 ton for a diesel. We are going to be doing a lot of travel and I know the diesel will pull a lot better in the mountains. I am trying to figure out if I will save any money with diesel being about 10% more expensive than gas.

My current 2011 gets about 9mpg towing at 60 to 65, trailer is 9500 pounds or so. What should I expect from a 2011-2014 Duramax diesel towing about 10,000 pounds? Anyone else towing an HT or Ultralight with a 3/4 ton Duramax?

[Skipmac]

Originally Posted by DavidJay

As we approach retirement, I am considering swapping my 6.0 powered Chevy 3/4 ton for a diesel. We are going to be doing a lot of travel and I know the diesel will pull a lot better in the mountains. I am trying to figure out if I will save any money with diesel being about 10% more expensive than gas.



My current 2011 gets about 9mpg towing at 60 to 65, trailer is 9500 pounds or so. What should I expect from a 2011-2014 Duramax diesel? Anyone else towing an HT or Ultralight with a 3/4 ton Duramax?

I have a 2017 1 ton SRW 6.6 pulling 14000 lb 5th wheel getting average 9.8 to 10 mpg. On hiway getting 19 to 20 diesel is same price as gas here

[GHen]

I have a 2017 2500 Duramax. Up and down major passes in the northwest I can average as little as 10.5 towing my 5th wheel. I stay at the speed limit no matter how steep it is. Up and down I-5 in Washington and Oregon I get around 12-14, towing. Best I get without towing on flat roads is around 23. Average back and forth to the hardware store which is stop and go is around 14.4, without towing. But I feel one of the best attributes is it’s Allison transmission, I hardly use the brakes at all when towing.

[Grumpy]

With my 2015, towing a PINNACLE, 62 to 65 mph was 10.75 to 11. Always used tow/haul mode and cruise as much as possible.

[oldmanAZ]

My diesel (not Duramax) mpg towing a smaller 5th wheel was right around 11 and sometimes 12mpg.

(BTW, I'm surprised you are getting that high (9mpg) with a gas engine. Include in your calculations, too, that diesels cost more to maintain and newer ones use DEF.)

[DavidJay]

Originally Posted by oldmanAZ

BTW, I'm surprised you are getting that high (9mpg) with a gas engine.

Well, that is flatland towing here in the upper Midwest.

[skijlw]

Our RV weighs in around 14K lbs. We travel mostly in the western states and cross many mountain passes. On average over a 1000 mile trip I get 11.5 at around 67 mph cruise. 2013 GMC 2500HD 4x4 crew cab

[SouthRider]

Have an 09 Duramax 3/4 ton 2wd single rear axle that we bought new.

Added a Banks programmer and air intake soon after purchase. Get 16 mpg commuting through rush hour traffic, and 11-12 towing a 9500 lb 5ver under 70 mph. FYI - the Banks air intake added about 1 mpg, the programmer maybe 1/2 mpg (BIG BUT - the programmer did make the vehicle 100% more driveable from idle to 30 mph. Newer models may not have that problem - it felt like the parking brake was on till we added the programmer).

Our vehicle is pre-DEF, but also cycles the DPF regularly which kills mileage. Our Audi diesel uses DEF but we never see or feel DPf regen happening - so there are trade-offs.

Have never checked our unloaded hwy mpg.

Trailer Life did an excellent comparison article a month or so ago. It's worth checking out. They validated my purchase of the diesel, but made honest factual comparisons. Part of the decision rests on your other needs.

[vegasguy]

I don't feel you are going to "save money" with a diesel. The higher cost to buy it, and maintain will off set any fuel savings.
What you will get is a more enjoyable towing experience. It will flat out cost more for a diesel, but you got to pay to play