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2021 GMC

Sierra 4WD

Auto 10-spd, 6 cyl, 3.0 L, Diesel, Turbo

GMC Sierra: best and worst years
2021 GMC Sierra 4WD (photo 1 of 2)

Closest available photo (2023 model year); you're viewing the 2021.

2023 photoEthan LlamasCC BY-SA 4.0Wikimedia Commons

Overview

Body
Standard Pickup Trucks 4WDEPA, from EPA, last updated 6/22/2026
Drivetrain
4-Wheel DriveEPA, from EPA, last updated 6/22/2026
Transmission
Automatic 10-spdEPA, from EPA, last updated 6/22/2026
Powertrain
DieselEPA, from EPA, last updated 6/22/2026
Fuel
DieselEPA, from EPA, last updated 6/22/2026

Engine & performance

Cyl
6EPA, from EPA, last updated 6/22/2026
Aspiration
TurbochargedEPA, from EPA, last updated 6/22/2026
Start-stop system
YesEPA, from EPA, last updated 6/22/2026

Efficiency

MPG Hwy
26 mpgEPA, from EPA, last updated 6/22/2026
MPG City
22 mpgEPA, from EPA, last updated 6/22/2026
MPG Comb
24 mpgEPA, from EPA, last updated 6/22/2026
Fuel $/yr
$3,250EPA, from EPA, last updated 6/22/2026
CO₂
430 g/miEPA, from EPA, last updated 6/22/2026
Eco Score
4/10EPA, from EPA, last updated 6/22/2026
Smog score
3/10
Elec. Range
0 miEPA, from EPA, last updated 6/22/2026
Real-world MPG
21.6 mpg, reported by 2 driversabout 2.4 mpg below the EPA combined estimate
SmartWay certified
No

Dimensions & capacity

Length
241 inNHTSA vPIC, from NHTSA vPIC, last updated 6/5/2026
Width
82 inNHTSA vPIC, from NHTSA vPIC, last updated 6/5/2026
Height
80 inNHTSA vPIC, from NHTSA vPIC, last updated 6/5/2026
Wheelbase
157 inNHTSA vPIC, from NHTSA vPIC, last updated 6/5/2026
Curb Weight
6,442 lbNHTSA vPIC, from NHTSA vPIC, last updated 6/5/2026

Safety NHTSA, model year

Recalls
0
Owner complaints
0

Warranty manufacturer terms, by make

Basic
3 yr / 36k mi
Powertrain
5 yr / 60k mi
Roadside assistance
5 yr / 60k mi
Maintenance
1 yr / 12k mi
EV battery
8 yr / 100k mi

Information is gathered on a best-effort basis from public sources, may be incomplete or out of date, and is not purchasing or financial advice. Verify with the manufacturer or dealer before buying.

2021 GMC Sierra 4WD Auto 10-spd, 6 cyl, 3.0 L, Diesel, Turbo · Trimslate