An 18 MPG combined fuel economy isn’t going to impress anyone looking for lower fuel costs, but it’s representative of what the 2016 GMC Sierra K15 4WD is: a full-size, four-wheel-drive truck with a strong 5.3L V8, built for hauling, towing, and tough jobs. Buyers know this, and they’re willing to accept the fuel cost for the capability and durability the Sierra offers.

City and highway performance

The EPA estimates for the 2016 Sierra K15 4WD are 16 MPG in the city and 22 MPG on the highway. The city estimate reflects the frequent stops, idling, and quicker acceleration common in cities, which impact fuel efficiency. The highway number is decent for a truck of this size and configuration. With its torquey 5.3L V8 and efficient six-speed automatic transmission, the Sierra cruises comfortably at highway speeds without burning excessive fuel. These estimates are based on standardized testing, so real-world conditions change actual mileage.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2016 GMC Sierra K15 4WD at $2,450. This is based on driving 15,000 miles per year and national average fuel prices. This is only an approximation. If you drive more than 15,000 miles annually, or if fuel prices in your area are higher, your actual fuel cost will be higher. Driving fewer miles or lower local fuel prices results in lower annual fuel costs. This provides a benchmark, but drivers should adjust it to their situation.

Real-world expectations

While the EPA estimates are a good guide, fuel economy changes based on driving habits, load, and terrain. Aggressive driving, frequent towing, or carrying heavy loads can lower fuel mileage. Gentle acceleration, consistent highway speeds, and regular maintenance can help improve it. If owners frequently use four-wheel drive when it’s not needed, this lowers fuel economy. The tires and their inflation pressure also affect fuel economy.

How it compares

When cross-shopping, comparing the 2016 Sierra K15 4WD to its competitors is helpful. A similarly equipped Ford F-150 4×4 with the 5.0L V8 engine from the same year typically gets around 17 MPG combined, making the Sierra’s 18 MPG slightly better. The Ram 1500 4×4 with the 5.7L Hemi V8 engine is similar, often reported around 17 MPG combined. Newer trucks have slightly better fuel efficiency due to engine technology and transmissions, but those looking at a 2016 model consider factors beyond just fuel economy. Buyers care about capability, reliability, and cost, knowing they’re driving a full-size truck, not a hybrid. Checking SIERRA MPG across all years shows improvements in later models.

Tips to maximize efficiency

Avoid aggressive driving. Rapid acceleration and hard braking burn more fuel than smooth driving. Anticipate traffic and keep a consistent speed when possible. The Sierra’s 5.3L V8 makes plenty of torque; using it carefully improves fuel economy.

Proper tire inflation is important. Check your tires and inflate them to the recommended pressure on the doorjamb sticker. Under-inflated tires increase rolling resistance, which lowers fuel efficiency. When it’s time for new tires, consider low rolling resistance tires.

Minimize idling. Idling wastes fuel. If you’re stopped for more than a minute or two, turn off the engine. Modern vehicles restart easily, so there’s no need to idle unless necessary.

Reduce weight and aerodynamic drag. Remove unnecessary items from the truck bed. Extra weight lowers fuel efficiency. Remove roof racks or accessories that increase aerodynamic drag when not in use. A cleaner vehicle is more aerodynamic and burns less fuel. Consider all all GMC fuel economy data when comparing fuel saving options.