2020 GMC Sierra fuel economy
The 2020 GMC Sierra is rated at 15–26 MPG combined by the EPA, from 15 MPG (5.3 L 8-cyl, Automatic 6-spd, Rear-Wheel Drive) to 26 MPG (3.0 L 6-cyl turbo, Automatic 10-spd, Rear-Wheel Drive). EPA size class: Standard Pickup Trucks 2WD, Standard Pickup Trucks 4WD, Special Purpose Vehicle 2WD, Special Purpose Vehicle 4WD.
MPG by version
| Version | City | Hwy | Comb. | L/100 km | UK MPG | Fuel cost/yr* |
|---|---|---|---|---|---|---|
| Sierra 2WD 3.0 L 6-cyl turbo, Automatic 10-spd, Rear-Wheel Drive · Diesel · Diesel | 23 | 30 | 26 | 9.0 | 31 | $3,700 |
| Sierra 4WD 3.0 L 6-cyl turbo, Automatic 10-spd, 4-Wheel Drive · Diesel · Diesel | 22 | 26 | 24 | 9.8 | 29 | $4,000 |
| Sierra 4WD AT4 3.0 L 6-cyl turbo, Automatic 10-spd, 4-Wheel Drive · Diesel · Diesel | 22 | 26 | 24 | 9.8 | 29 | $4,000 |
| Sierra 2WD 2.7 L 4-cyl turbo, Automatic 8-spd, Rear-Wheel Drive · Regular Gasoline | 20 | 23 | 21 | 11.2 | 25 | $3,200 |
| Sierra 2WD 2.7 L 4-cyl turbo, Automatic 8-spd, Rear-Wheel Drive · Regular Gasoline | 19 | 22 | 20 | 11.8 | 24 | $3,350 |
| Sierra 2WD 5.3 L 8-cyl, Automatic 8-spd, Rear-Wheel Drive · Regular Gasoline | 17 | 24 | 20 | 11.8 | 24 | $3,350 |
| Sierra 4WD 2.7 L 4-cyl turbo, Automatic 8-spd, 4-Wheel Drive · Regular Gasoline | 19 | 22 | 20 | 11.8 | 24 | $3,350 |
| Sierra 2WD 5.3 L 8-cyl, Automatic 8-spd, Rear-Wheel Drive · Regular Gasoline | 17 | 23 | 19 | 12.4 | 23 | $3,550 |
| Sierra 4WD 5.3 L 8-cyl, Automatic 10-spd, 4-Wheel Drive · Regular Gasoline | 16 | 22 | 19 | 12.4 | 23 | $3,550 |
| Sierra 4WD 5.3 L 8-cyl, Automatic 8-spd, 4-Wheel Drive · Regular Gasoline | 16 | 22 | 18 | 13.1 | 22 | $3,700 |
| Sierra 4WD AT4 5.3 L 8-cyl, Automatic 10-spd, 4-Wheel Drive · Regular Gasoline | 16 | 21 | 18 | 13.1 | 22 | $3,700 |
| Sierra 4WD AT4 5.3 L 8-cyl, Automatic 8-spd, 4-Wheel Drive · Regular Gasoline | 16 | 21 | 18 | 13.1 | 22 | $3,700 |
| Sierra 2WD 4.3 L 6-cyl, Automatic 6-spd, Rear-Wheel Drive · Regular Gasoline | 16 | 21 | 17 | 13.8 | 20 | $3,950 |
| Sierra 2WD 5.3 L 8-cyl, Automatic 6-spd, Rear-Wheel Drive · Regular Gasoline | 15 | 21 | 17 | 13.8 | 20 | $3,950 |
| Sierra 4WD 4.3 L 6-cyl, Automatic 6-spd, 4-Wheel Drive · Regular Gasoline | 15 | 20 | 17 | 13.8 | 20 | $3,950 |
| Sierra 4WD 5.3 L 8-cyl, Automatic 6-spd, 4-Wheel Drive · Regular Gasoline | 15 | 20 | 17 | 13.8 | 20 | $3,950 |
| Sierra 4WD 6.2 L 8-cyl, Automatic 10-spd, 4-Wheel Drive · Premium Gasoline | 15 | 20 | 17 | 13.8 | 20 | $4,850 |
| Sierra 4WD AT4 6.2 L 8-cyl, Automatic 10-spd, 4-Wheel Drive · Premium Gasoline | 15 | 19 | 17 | 13.8 | 20 | $4,850 |
| Sierra Cab Chassis 2WD 4.3 L 6-cyl, Automatic 6-spd, Rear-Wheel Drive · Regular Gasoline | 15 | 19 | 17 | 13.8 | 20 | $3,950 |
| Sierra 2WD 5.3 L 8-cyl, Automatic 6-spd, Rear-Wheel Drive · Flex-fuel · Regular Gasoline | 15 | 19 | 16 | 14.7 | 19 | $4,200 |
| Sierra 4WD 5.3 L 8-cyl, Automatic 6-spd, 4-Wheel Drive · Flex-fuel · Regular Gasoline | 14 | 19 | 16 | 14.7 | 19 | $4,200 |
| Sierra 4WD AT4 5.3 L 8-cyl, Automatic 6-spd, 4-Wheel Drive · Regular Gasoline | 14 | 18 | 16 | 14.7 | 19 | $4,200 |
| Sierra Cab Chassis 2WD 5.3 L 8-cyl, Automatic 6-spd, Rear-Wheel Drive · Regular Gasoline | 14 | 18 | 15 | 15.7 | 18 | $4,450 |
| Sierra Cab Chassis 4WD 4.3 L 6-cyl, Automatic 6-spd, 4-Wheel Drive · Regular Gasoline | 14 | 16 | 15 | 15.7 | 18 | $4,450 |
| Sierra Cab Chassis 4WD 5.3 L 8-cyl, Automatic 6-spd, 4-Wheel Drive · Regular Gasoline | 14 | 17 | 15 | 15.7 | 18 | $4,450 |
* EPA estimate of yearly fuel (or electricity) cost for 15,000 miles with 55 % city driving, at the fuel prices EPA used for this model year. Use the fuel cost comparison with your own mileage and prices.
About these numbers
EPA ratings come from standard laboratory tests adjusted to reflect real-world driving, so they are best for comparing vehicles. Your own figure will vary with speed, temperature, load, tires and driving style — measure it with the MPG calculator. If you have fitted larger tires, correct the reading with the tire size and fuel economy calculator.
Source: U.S. Environmental Protection Agency and U.S. Department of Energy, fueleconomy.gov. Original data (downloaded 2026-09-29). Data processed by us; errors in processing are ours, not the publisher's.