2021 GMC Sierra Cab Chassis
17MPG
Combined
6
Trims
Updated February 27, 2026
The 2021 GMC Sierra Cab Chassis is a Special Purpose Vehicle 2WD that delivers 14–17 combined MPG depending on trim. Here’s everything you need to know about this vehicle, from fuel economy to safety ratings.
2021 GMC Sierra Cab Chassis Specifications
| Spec | Value |
|---|---|
| Combined MPG | 14–17 combined MPG depending on trim |
| City MPG | 15 |
| Highway MPG | 19 |
| Body Style | Special Purpose Vehicle 2WD |
| Fuel Type | Regular |
| Drive | RWD |
| Available Trims | 6 |
Available Trims
| Trim | MPG (City/Hwy/Combined) | Engine | Transmission |
|---|---|---|---|
| Auto | 14/18/15 | 5.3L 8cyl | Automatic 6-spd |
| Auto | 15/19/17 | 4.3L 6cyl | Automatic 6-spd |
| Auto | 13/18/14 | 5.3L 8cyl | Automatic 6-spd |
| Auto | 14/17/15 | 5.3L 8cyl | Automatic 6-spd |
| Auto | 14/16/15 | 4.3L 6cyl | Automatic 6-spd |
| Auto | 13/17/14 | 5.3L 8cyl | Automatic 6-spd |
Annual Fuel Cost
Based on EPA estimates, the 2021 GMC Sierra Cab Chassis costs approximately $2,958 per year in fuel. This assumes 15,000 miles driven annually and current fuel prices.
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- 2021 (this page)
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