2021 GMC Sierra Cab Chassis 4WDFuel Economy & MPG Ratings

Gasoline Special Purpose Vehicle 4WD4-Wheel Drive
2021 GMC Sierra Cab Chassis 4WD

Photo: sv1ambo. CC BY 2.0. via Wikimedia Commons

City
14
MPG
Highway
17
MPG
Combined
15
MPG

Trim Comparison

Automatic 6-spd
Regular
City
14
Hwy
17
Comb
15
Fuel cost: $4,500/yr
Automatic 6-spd
Regular
City
14
Hwy
16
Comb
15
Fuel cost: $4,500/yr
Automatic 6-spd
Regular
City
13
Hwy
17
Comb
14
Fuel cost: $4,800/yr
Annual Fuel Cost
$4,500

Based on gasoline at $3.67/gal, 15,000 miles/year

5-Year Fuel Savings
$-10,500

vs. average new vehicle

EPA Fuel Economy Score: 2/10
GHG Score: 2/10

Environment

CO₂ Tailpipe Emissions
593 g/mile
Annual Petroleum Consumption
19.8 barrels

Specifications

Engine
5.3L 8-cyl
Transmission
6-speed Automatic
Drivetrain
4WD
Body Style
Special Purpose Vehicle 4WD

Source: EPA fuel economy data & NHTSA vPIC. Specifications reflect the most common trim configuration.

Engine & Efficiency Details

Source: EPA fueleconomy.gov

Engine Size
5.3L, 8-cylinder
Induction Type
Direct Injection
Fuel Type
Regular Gasoline

Annual Fuel Cost by State

Prices as of week ending May 18, 2026 · Source: EIA

National AvgEPA default
$4.490/gal$4,490/yr
California
$5.957/gal$5,957/yr
Texas
$3.888/gal$3,888/yr
Florida
$4.136/gal$4,136/yr
New York
$4.522/gal$4,522/yr
Ohio
$4.510/gal$4,510/yr
Washington
$5.591/gal$5,591/yr
Colorado
$4.618/gal$4,618/yr
Minnesota
$4.344/gal$4,344/yr
Massachusetts
$4.448/gal$4,448/yr

Calculated at 15,000 miles/year (EPA standard assumption) using 15 MPG combined. Regular gasoline prices. Actual costs vary.

Recall History

Source: NHTSA

No recalls reported for this vehicle.

Owner-Reported Problems482 complaints

Source: NHTSA

NHTSA has received 482 owner complaints for the 2021 GMC Sierra Cab Chassis 4WD. Top reported issues include engine, power train and electrical system. The data below is sourced from consumer complaints filed directly with NHTSA.

Problems by System / Component

Engine
291
Power Train
114
Electrical System
65
Fuel System
29
Steering
29
Brakes
22
Advanced Safety (ADAS)
13
Structure
10

2021 GMC Sierra Cab Chassis 4WD problems by category: Engine: 291 complaints, Power Train: 114 complaints, Electrical System: 65 complaints, Fuel System: 29 complaints, Steering: 29 complaints, Brakes: 22 complaints, Advanced Safety (ADAS): 13 complaints, Structure: 10 complaints.

7
Crashes Reported
12
Fires Reported
2
Injuries Reported

Sample Owner Complaints

EngineFiled: 04/09/2026ODI#11730203
See attached document for complaint. INFORMATION, DETAILS, COMMENTS, DATES, AND NUMBERS ON RECALL 20211500 DENALI Recall Vehicle Information: All models of GM's with 6.2L gas engine (My personal truc…
Power TrainFiled: 04/28/2025ODI#11657385
See attached vehicle repair orders/Carfax/vehicle registration. The trucks transmission has been slipping/jerking hard since I pulled off the lot at dealer ship. Its burning oil no leaks has bee…
Power TrainFiled: 03/12/2025ODI#11647961
[XXX], I PURCHASED A 2021 GMC SIERRA 1500 FROM FAULKNER CHEVROLET IN BETHLEHEM, PA. I TEST DROVE THE VEHICLE BEFORE PURCHASE AND IT SHOWED NO INDICATION OF ANY MECHANICAL ISSUES THAT I WAS ABLE TO DET…

Complaint data is sourced from the NHTSA Complaints Database. Reports are filed by vehicle owners and may not reflect confirmed defects. Last updated via NHTSA API.

Related

GMC Sierra Cab Chassis 4WD MPG History
See how this model's fuel economy changed by year

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