The 2018 GMC Sierra C15 2WD with the 5.3L V8 engine gets 19 MPG combined. This isn’t great, especially with hybrid trucks and improving efficiency available. However, this Sierra is a reliable tool. It is built for those who need to haul, tow, and get the job done. The fuel economy is a necessary compromise for the capability it offers, a trade-off understood by the truck’s buyers.

City and highway performance

The EPA estimates for the Sierra are 16 MPG in the city and 23 MPG on the highway. The city MPG reflects stop-and-go traffic, where the truck’s weight and engine displacement hurt efficiency. The highway MPG is more respectable, aided by the 6-speed automatic transmission that lets the V8 cruise at a relatively low RPM. Regular maintenance, proper tire inflation, and avoiding aggressive acceleration will help you achieve, or slightly exceed, these estimates.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2018 GMC Sierra C15 2WD 5.3L V8 at $2,300. This is based on 15,000 miles per year, using fuel at the national average price. If you drive more than 15,000 miles, or if fuel prices are higher in your area, your costs will likely exceed $2,300. If you drive fewer miles or have lower local fuel prices, you could spend less. The $2,300 is a benchmark for comparing fuel costs across vehicles.

Real-world expectations

While the EPA estimates provide a baseline, real-world MPG varies. Driving style, load weight, towing frequency, and terrain all play a role. Drivers who frequently tow or haul heavy loads will see decreased fuel economy. Aggressive driving, such as hard acceleration and frequent braking, will also hurt MPG. However, those who accelerate smoothly and maintain a consistent speed on the highway can get closer to, or slightly exceed, the EPA’s estimates. Remember that SIERRA MPG across all years reflects its intended use.

How it compares

The 2018 Ford F-150 with its 2.7L EcoBoost V6 engine achieves a better 22 MPG combined. The F-150 offers less raw power and towing capacity than the Sierra’s 5.3L V8, however. A similarly equipped Chevrolet Silverado 1500, sharing the same engine and drivetrain, offers nearly identical fuel economy, so the choice is about looks and personal preference. The Ram 1500 with the 5.7L Hemi V8 gets about 17-19 MPG combined depending on configuration, nearly the same as the Sierra. These comparisons matter to buyers who need a full-size truck’s capability but worry about fuel costs. They’re weighing power and utility against their budgets, looking for the best balance.

Tips to maximize efficiency

Start by practicing smooth acceleration and braking. The Sierra 1500 already has a heavy curb weight, and aggressive driving only makes it worse. Anticipate traffic flow and avoid sudden bursts of speed.

Maintain proper tire inflation. Underinflated tires increase rolling resistance, making the engine work harder and burn more fuel. Check your tire pressure regularly and inflate to the recommended levels on the doorjamb sticker.

Minimize idling. Leaving the engine running while stopped consumes extra fuel. If you’ll be stopped for more than a minute, turn off the engine. The 5.3L V8 restarts quickly and reliably, which saves fuel.

Reduce aerodynamic drag. Remove unnecessary roof racks or cargo carriers when not in use. These increase wind resistance and hurt fuel economy, especially at highway speeds.

Consider using cruise control on the highway. Maintaining a consistent speed minimizes unnecessary acceleration and deceleration, which reduces fuel consumption. Pay attention to the terrain, and be ready to disengage cruise control on steep hills to avoid excessive downshifting and fuel burn. You can see all Gmc fuel economy data if you’re looking for alternative vehicles.