Average Fuel Economy of Duramax Diesel Engine Trucks

The Duramax diesel engine is predominately found in GMC trucks. It was introduced in 2001 and has gone through many updates. The current version (2017+) is a 6.6L turbo-diesel V8 which has some of the best torque and horsepower you could ever want in a diesel engine.

There is also a smaller 2.8 liter version of the Duramax diesel turbo-diesel engine that can be found on 2016+ Chevy Colorado and GMC Canyon midsize pickups. Rather than the 910 pound-foot of torque found with the 6.6L engine, the 2.8L 4-Cylinder Turbodiesel offers 369 pound-foot of torque. However, both give users great gas mileage as we as the power you would expect from a diesel engine.

Duramax engine fuel economy

Duramax MPG for 5 Most Common Trucks

When people shop around for trucks of any size, in addition to torque and towing capacity, they likely want to know the miles per gallon that they’ll get out of it. Duramax diesel engines are made to enhance fuel efficiency so that you get the most miles per gallon out of your truck that is possible.

Below are 5 common vehicles which have a Duramax diesel engine in them. Because manufacturer based MPG numbers are usually unrealistic, the fuel mileages shown below are taken from hundreds of actual owners of the vehicles themselves, millions of miles driven, and actually putting the trucks through typical days of work (courtesy of Fuelly.com).

Note: Obviously, the actual fuel economy achieved is based on many factors (speed, driving style, weight, towing, etc.) so your results may vary but this should give you a good idea of “real-world” usage.

#1 – Chevrolet Silverado 2500HD

YearAverage Miles Per GallonYearAverage Miles Per Gallon
200115.4 MPG200215.0 MPG
200314.9 MPG200414.3 MPG
200513.9 MPG200614.3 MPG
200714.6 MPG200814.5 MPG
200913.4 MPG201014.7 MPG
201113.7 MPG201213.3 MPG
201314.9 MPG201414.3 MPG
201514.2 MPG201614.3 MPG
201714.3 MPG201814.4 MPG
201914.9 MPG

#2 – GMC Sierra 2500HD

YearAverage Miles Per GallonYearAverage Miles Per Gallon
200114.2 MPG200215.0 MPG
200315.2 MPG200415.5 MPG
200513.6 MPG200614.7 MPG
200714.3 MPG200814.4 MPG
200914.6 MPG201015.0 MPG
201113.9 MPG201213.7 MPG
201313.4 MPG201413.7 MPG
201513.9 MPG201614.4 MPG
201714.5 MPG201815.5 MPG
201914.8 MPG

#3 – GMC Sierra 3500HD

YearAverage Miles Per GallonYearAverage Miles Per Gallon
200713.6 MPG200813.3 MPG
200915.1 MPG201013.2 MPG
201113.7 MPG201213.3 MPG
201312.5 MPG201412.2 MPG
201514.3 MPG201612.6 MPG
201713.3 MPG201811.8 MPG
201914.3 MPG

#4 – Chevrolet Colorado

YearAverage Miles Per GallonYearAverage Miles Per Gallon
201623.9 MPG201723.8 MPG
201822.9 MPG201923.0 MPG

#5 – GMC Canyon

YearAverage Miles Per GallonYearAverage Miles Per Gallon
201623.6 MPG201724.3 MPG
201824.8 MPG

General Motors owns the brand and rights to the Duramax diesel engine. The company currently has a joint venture with the Japanese motor company called Isuzu. This joint venture is referred to as DMAX, which is the manufacturer of Duramax diesel engines.

The engine became popular after they were first installed in the 2001 GMC and Chevrolet trucks. Ever since then, GMC has given people the option to have a Duramax diesel engine in all the medium-sized trucks, vans, and pickup trucks that they sell. If you come across this option, be sure to take it.



  1. While driving in the right most lane on level highway at 65 miles per hour I can pull 24 mpg with the Duramax diesel 6.6L in my Silverado 2500HD truck.

  2. I was hoping somebody had tried success getting better mileage. I’m picking up a 2008 with 220k on it this week. If you don’t mind my asking, what year is your truck, Jim?

  3. The results above are based on “real-world” scenarios of thousands of drivers so there’s no way to know but I’d assume most are running their trucks stock or close to it.

  4. 2019 duramax crewcab srw getting 24mpg hwy, level road 65mph Standard factorry equipment? Encouraging to know if that is true. Can changing filters, exhaust or anything else increase mpg?

    • So much of MPG is based on driving style but yes, I do believe you can increase mileage from a better intake, a more free-flowing exhaust (sometimes), or custom fuel mapping. If someone really wanted to, I bet they could get close to 30 MPG with a Duramax.

  5. I have a GMC Sierra SLE 2007 3/4 ton (2500)LBZ 6.6 Duramax with a 6 speed Allison Transmission. Pulling a huge load at 50mph in 4 gear I get about 10 mpg. Pulling a medium load in 5th gear at 62mph I get about 14mpg. Empty on the highway driving 63mph I get about 20mpg. Empty at 70mph I get about 18mpg. I have 235K on the engine. It still runs great! The size of the load and amount of wind can and will make a difference. Change oil & filter every 7500 with Valvoline Blue Extreme. Change the transmission filters, fluid and the pumpkins every 100K with Amzoil synthetic recommended viscosity’s. Rocker panels are starting to rust. ($5K to repair at the bodyshop) I was in the dealership today to price out a new one, about $60K for a GMC Sierra SLE no leather crewcab and a long bed. Thinking about it or just purchasing another used GMC duramax. I don’t think I would ever go back to a gas engine, I love the power of the diesel!

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