The 2020 GMC Sierra 4WD with the 6.2L V8 gets 17 MPG combined, which isn’t record-breaking. This truck isn’t purchased for its fuel sipping abilities. It’s bought because it’s a workhorse, a tow rig, and a statement, and because its driver needs serious capability, regardless of what the pump says. This is the Sierra for those who prioritize power and presence over pinching pennies, a truck engineered for hauling heavy loads, conquering challenging terrain, and making a bold statement wherever it goes.

City and highway performance

The EPA estimates for the 2020 GMC Sierra 6.2L 4WD place city driving at 15 MPG and highway runs at 20 MPG. This difference reflects the significant load placed on the engine during stop-and-go conditions. City driving necessitates frequent acceleration from a standstill, which demands more fuel than maintaining a steady speed on the highway. The 10-speed automatic transmission helps to optimize fuel use at different speeds, but the 6.2L V8 needs a certain amount of fuel to generate its power. The highway number of 20 MPG is more palatable, especially during long road trips and when the Sierra is unladen.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2020 GMC Sierra 6.2L 4WD at $3,400. This number is based on driving 15,000 miles per year, using a blend of 55% city and 45% highway driving, and using national average fuel prices. Remember that this is just an estimate. Your actual fuel costs will vary depending on your driving habits, the type of fuel you use, and prevailing fuel prices in your area. Drivers who spend most of their time towing construction equipment, for instance, can expect to significantly exceed this figure.

Real-world expectations

While the EPA figures provide a standardized benchmark, real-world fuel economy for the 2020 GMC Sierra 6.2L 4WD will vary. Drivers who regularly tow trailers or haul heavy loads will likely see significantly lower fuel economy than the EPA estimates. Aggressive driving, frequent short trips (where the engine doesn’t reach optimal operating temperature), and extreme weather conditions will also negatively influence fuel consumption. Conversely, drivers who primarily use their Sierra for highway commuting, and who drive conservatively, have a greater chance of potentially matching or even slightly exceeding the EPA’s 20 MPG highway estimate. It’s crucial to calibrate your expectations based on your individual driving patterns. It’s worthwhile to check SIERRA MPG across all years if you’re looking at different configurations to see how they compare.

How it compares

Compared to other full-size, four-wheel-drive trucks with powerful V8 engines, the 2020 GMC Sierra 6.2L 4WD’s fuel economy is generally in line with expectations. For example, the comparable Ford F-150 with its 5.0L V8 and four-wheel drive achieves roughly the same EPA estimates, around 17 MPG combined. A Ram 1500 equipped with the 5.7L Hemi V8 and four-wheel drive offers similar numbers as well. These trucks, while offering a diverse range of features and capabilities, operate within a relatively narrow fuel economy band when equipped with similar engine configurations and drivetrains. Drivers considering a Sierra 6.2L are likely already aware of the fuel economy trade-offs compared to, say, choosing a Silverado with the 2.7L turbo (rated around 20 MPG combined), but they’re prioritizing the V8’s power.

Tips to maximize efficiency

Given its powerful engine and four-wheel-drive system, small adjustments may help you gain a little more for each spend at the gas pump. Reduce aggressive acceleration and hard braking, as these maneuvers significantly increase fuel consumption. The 6.2L engine is responsive so gentle acceleration and using the engine’s torque make the most sense.

Ensure your tires are properly inflated, as underinflated tires increase rolling resistance and reduce fuel economy. Check your tires monthly and inflate them to the manufacturer-recommended pressure. This is especially important when towing with the Sierra, as incorrect tire pressure could be unsafe in addition to reducing efficiency.

When practical, remove any unnecessary weight from the truck bed. Carrying heavy items reduces fuel economy, especially during city driving. This is an easy way to reduce strain on the V8 engine and cut down on fuel consumption for all Gmc fuel economy data.

Consider using cruise control on the highway to maintain a consistent speed. Consistent speeds minimize throttle adjustments and help to optimize fuel consumption. Modern cruise control systems manage fuel consumption more efficiently than older systems.

For shorter trips around town, consider engaging the Sierra’s two-wheel drive mode when four-wheel drive isn’t needed. Four-wheel drive increases drivetrain friction and reduces fuel economy. When four-wheel drive is unnecessary, switching to two-wheel drive is an almost instant efficiency upgrade.