The 2021 GMC Sierra 1500 is the third model year for the latest fourth-generation nameplate, following up on a complete overhaul for the 2019 model year. In addition to offering loads of capability, sharp styling, and the latest tech features, the new 2021 GMC Sierra 1500 diesel also offers impressive fuel efficiency, besting even the GMC Canyon diesel in official mpg ratings.
GMC Sierra 1500
GMC Canyon
According to the EPA, the 2021 GMC Sierra 1500 diesel is rated at 23 mpg in the city, 30 mpg on the highway, and 26 mpg combined when equipped with 2WD, with an estimated annual fuel cost of $1,450. By comparison, the 2021 GMC Canyon diesel is rated at 20 mpg in the city, 30 mpg on the highway, and 23 mpg combined when equipped with 2WD, with an estimated annual fuel cost of $1,650.
The addition of 4WD puts a small dent in the mpg ratings for both models, with 4WD 2021 GMC Sierra 1500 diesel models rated at 22 mpg in the city, 26 mpg on the highway, and 24 mpg combined, with an estimated annual fuel cost of $1,600. However, those figures still best the 4WD 2021 GMC Canyon diesel in two of the three ratings, with the 4WD Canyon rated at 19 mpg in the city, 28 mpg on the highway, and 22 mpg combined, with an annual estimated fuel cost of $1,700.
| Model | Engine | Drivetrain | City MPG | Highway MPG | Combined MPG |
|---|---|---|---|---|---|
| Sierra | Turbo 3.0L I6 LM2 | 2WD | 23 | 30 | 26 |
| Sierra | Turbo 3.0L I6 LM2 | 4WD | 22 | 26 | 24 |
| Canyon | Turbo 2.8L I4 LWN | 2WD | 20 | 30 | 23 |
| Canyon | Turbo 2.8L I4 LWN | 4WD | 19 | 28 | 22 |
To note, the 2021 GMC Sierra 1500 diesel is equipped with a more modern powerplant compared to the Canyon diesel, with the former running the 3.0L I6 LM2 turbo-diesel Duramax, rated at 277 horsepower and 460 pound-feet of torque, while the latter is equipped with the 2.8L I4 LWN turbo-diesel Duramax, which is rated at 181 horsepower and 369 pound-feet of torque.
Not only is the 2021 GMC Sierra 1500 diesel running a more modern engine, but it also has a more modern transmission compared to the GMC Canyon diesel, routing power through the 10-speed MQB automatic, as opposed to the six-speed MYB automatic equipped in the GMC Canyon diesel.
Add it all up, and the Sierra 1500 diesel simply sips fuel, even compared to the GMC Canyon diesel.
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Comments
Put the 10 speed auto behind the 2.8L diesel in the Canyon, and it will surpass the Sierra’s MPG. The diesel is the one thing makes the Colorado and Canyon unique. They still don’t discount those diesel models even after 4 years of availability. The 2.8L had performed well in the Express van too. It’s a little old school, but it’s a stout engine with good efficiency.
The 3.0L (in the full sized trucks) is a truly great unit. Not wild about the placement of the oil pump belt, but other than that it looks like an incredible motor. It’s easily the best half ton diesel on the market. Possibly the best motor in the half ton segment depending on your needs.
And the highway rating is about 4 less than what many 4X4 buyers are reporting in the real world on the full sized trucks and proof how flawed the EPA still is!