2021 GMC Sierra 4WD At4

Truck Premium
GMC Sierra 4WD At4 2021
24MPG Combined
8 Trims
← 2020 2021
Updated February 27, 2026

Get the full picture on the 2021 GMC Sierra 4WD At4. As a Truck, it achieves 16–24 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 4WD At4 Specifications

SpecValue
Combined MPG16–24 combined MPG depending on trim
City MPG22
Highway MPG26
Body StyleTruck
Fuel TypePremium
Drive4WD
Available Trims8

Available Trims

TrimMPG (City/Hwy/Combined)EngineTransmission
Auto15/19/176.2L 8cylAutomatic 10-spd
Auto22/26/243.0L 6cylAutomatic 10-spd
Auto16/21/185.3L 8cylAutomatic 10-spd
Auto16/21/185.3L 8cylAutomatic 8-spd
Auto14/18/165.3L 8cylAutomatic 6-spd
Auto14/20/165.3L 8cylAutomatic 8-spd
Auto14/19/166.2L 8cylAutomatic 10-spd
Auto15/21/175.3L 8cylAutomatic 10-spd

Annual Fuel Cost

Based on EPA estimates, the 2021 GMC Sierra 4WD At4 costs approximately $2,800 per year in fuel. This assumes 15,000 miles driven annually and current fuel prices.

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