2021 GMC Sierra

Truck Regular
GMC Sierra 2021
26MPG Combined
22 Trims
← 2020 2021 2022 →
Updated February 27, 2026

Get the full picture on the 2021 GMC Sierra. As a Truck, it achieves 16–26 combined MPG depending on trim and has not yet been rated by NHTSA. Below you’ll find detailed specs for every trim, plus recall information and competitor comparisons.

2021 GMC Sierra Specifications

SpecValue
Combined MPG16–26 combined MPG depending on trim
City MPG23
Highway MPG30
Body StyleTruck
Fuel TypeRegular
DriveRWD
Available Trims22

Available Trims

TrimMPG (City/Hwy/Combined)EngineTransmission
Auto15/21/175.3L 8cylAutomatic 6-spd
Auto15/19/165.3L 8cylAutomatic 6-spd
Auto17/23/195.3L 8cylAutomatic 8-spd
Auto23/30/263.0L 6cylAutomatic 10-spd
Auto16/21/174.3L 6cylAutomatic 6-spd
Sport20/23/212.7L 4cylAutomatic 8-spd
Auto20/23/212.7L 4cylAutomatic 8-spd
Auto14/21/165.3L 8cylAutomatic 6-spd
Auto15/22/175.3L 8cylAutomatic 8-spd
Auto16/20/176.2L 8cylAutomatic 10-spd
Auto15/20/175.3L 8cylAutomatic 6-spd
Auto14/18/165.3L 8cylAutomatic 6-spd
Auto22/26/243.0L 6cylAutomatic 10-spd
Auto16/22/195.3L 8cylAutomatic 10-spd
Auto16/21/185.3L 8cylAutomatic 8-spd
Auto15/20/174.3L 6cylAutomatic 6-spd
Sport18/21/192.7L 4cylAutomatic 8-spd
Auto18/20/192.7L 4cylAutomatic 8-spd
Auto14/20/165.3L 8cylAutomatic 6-spd
Auto14/20/165.3L 8cylAutomatic 8-spd
Auto15/20/166.2L 8cylAutomatic 10-spd
Auto15/21/185.3L 8cylAutomatic 10-spd

Annual Fuel Cost

Based on EPA estimates, the 2021 GMC Sierra costs approximately $2,570 per year in fuel. This assumes 15,000 miles driven annually and current fuel prices.

Compare the 2021 GMC Sierra

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