MPG & Fuel Economy Data
The 2021 GMC Sierra 4WD AT4 has an estimated 17.0 MPG combined. This premium gasoline-powered vehicle offers 15.0 MPG in the city and 19.0 MPG on the highway. Check out its full EPA-estimated fuel economy data below.
Combined17.0 MPG
City15.0 MPG
Highway19.0 MPG
CO₂ Emissions522 g/mi
GHG Score3/10
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With a Greenhouse Gas Score of 3/10, the 2021 GMC Sierra 4WD AT4 has below average environmental performance in its class. If you prefer more environmentally friendly alternatives, compare this vehicle's fuel economy with others in this class.
The vehicle produces approximately 522 grams of CO₂ per mile under typical driving conditions. Consider more fuel-efficient alternatives if environmental impact is a priority.
This standard pickup trucks 4wd features a 6.2L 8-cylinder engine, paired with a automatic 10-spd transmission and 4-wheel drive drivetrain. It includes start-stop technology to improve fuel efficiency in city driving conditions.
To achieve the best fuel economy in your 2021 GMC Sierra 4WD AT4, consider these tips:
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This Fuel Savings Calculator tool is provided for informational and educational purposes only. The MPG data used is sourced from the U.S. Environmental Protection Agency (EPA), an official government resource, and while efforts are made to ensure accuracy, discrepancies or updates may occur. Calculations are based on standard assumptions and estimates, which may not reflect individual circumstances or real-world conditions. Users are responsible for verifying results with their own data and should consult additional resources or/and professionals for critical decisions. This tool is provided "as is" without warranties of any kind, and the developers disclaim any liability for decisions or actions taken based on its output. The tool may be updated or modified without notice, affecting its functionality or results. By using this tool, you acknowledge and agree to these terms.
The 2021 GMC Sierra 4WD AT4 with auto 8-spd has an estimated 18.0 MPG combined. This auto 8-spd regular gasoline-powered vehicle offers 16.0 MPG in the city and 21.0 MPG on the highway.
Combined18.0 MPG
City16.0 MPG
Highway21.0 MPG
CO₂ Emissions484 g/mi
GHG Score3/10
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When using regular gasoline, the 2021 GMC Sierra 4WD AT4 with auto 8-spd has a carbon footprint of 484 grams of CO₂ per mile. Its Greenhouse Gas Score of 3/10 indicates its relative environmental impact, with higher scores representing lower emissions.
These environmental metrics reflect the vehicle's efficiency in auto 8-spd configuration. The CO₂ emissions measurement provides a direct indicator of the vehicle's contribution to greenhouse gases, while the GHG score offers a standardized comparison with other vehicles in its class.
This variant includes start-stop technology, which can help reduce emissions and fuel consumption during city driving by automatically shutting off the engine when the vehicle is stationary.
This standard pickup trucks 4wd with auto 8-spd features a 5.3L 8-cylinder engine and 4-wheel drive drivetrain. It includes start-stop technology to improve fuel efficiency in city driving conditions.
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The 2021 GMC Sierra 4WD AT4 with auto 6-spd has an estimated 16.0 MPG combined. This auto 6-spd regular gasoline-powered vehicle offers 14.0 MPG in the city and 18.0 MPG on the highway.
Combined16.0 MPG
City14.0 MPG
Highway18.0 MPG
CO₂ Emissions543 g/mi
GHG Score2/10
*As an Amazon Associate, we earn from qualifying purchases.
When using regular gasoline, the 2021 GMC Sierra 4WD AT4 with auto 6-spd has a carbon footprint of 543 grams of CO₂ per mile. Its Greenhouse Gas Score of 2/10 indicates its relative environmental impact, with higher scores representing lower emissions.
These environmental metrics reflect the vehicle's efficiency in auto 6-spd configuration. The CO₂ emissions measurement provides a direct indicator of the vehicle's contribution to greenhouse gases, while the GHG score offers a standardized comparison with other vehicles in its class.
This standard pickup trucks 4wd with auto 6-spd features a 5.3L 8-cylinder engine and 4-wheel drive drivetrain.
*As an Amazon Associate, we earn from qualifying purchases.
The 2021 GMC Sierra 4WD AT4 with auto 8-spd has an estimated 16.0 MPG combined. This auto 8-spd regular gasoline-powered vehicle offers 14.0 MPG in the city and 20.0 MPG on the highway.
Combined16.0 MPG
City14.0 MPG
Highway20.0 MPG
CO₂ Emissions551 g/mi
GHG Score2/10
*As an Amazon Associate, we earn from qualifying purchases.
When using regular gasoline, the 2021 GMC Sierra 4WD AT4 with auto 8-spd has a carbon footprint of 551 grams of CO₂ per mile. Its Greenhouse Gas Score of 2/10 indicates its relative environmental impact, with higher scores representing lower emissions.
These environmental metrics reflect the vehicle's efficiency in auto 8-spd configuration. The CO₂ emissions measurement provides a direct indicator of the vehicle's contribution to greenhouse gases, while the GHG score offers a standardized comparison with other vehicles in its class.
This variant includes start-stop technology, which can help reduce emissions and fuel consumption during city driving by automatically shutting off the engine when the vehicle is stationary.
This standard pickup trucks 4wd with auto 8-spd features a 5.3L 8-cylinder engine and 4-wheel drive drivetrain. It includes start-stop technology to improve fuel efficiency in city driving conditions.
*As an Amazon Associate, we earn from qualifying purchases.
17.0 MPG
View detailed fuel economy data
17.0 MPG
View detailed fuel economy data
17.0 MPG
View detailed fuel economy data
These vehicles are in the same class (Standard Pickup Trucks 4WD) and offer comparable fuel economy ratings.