17 MPG combined may be hard for many modern truck buyers to accept. But for those who specifically want the 2019 GMC Sierra C10 2WD with the 5.3L V8, it’s the reality. These buyers aren’t prioritizing efficiency above all else; they value the proven reliability and strong power of this engine configuration for towing, hauling, and general truck duties. They understand that a lightweight, rear-wheel-drive truck with a traditional V8 isn’t going to sip fuel quite like a crossover, and they’re willing to make that trade-off.

City and highway performance

The EPA estimates the 2019 Sierra C10 5.3L at 15 MPG in the city and 21 MPG on the highway. The city figure reflects the engine’s performance in stop-and-go traffic, where frequent acceleration and idling significantly impact fuel consumption. The highway rating, on the other hand, shows the engine’s potential when cruising at a steady speed, though even then, the Sierra’s large frontal area and relatively basic 6-speed automatic transmission hold it back compared to more modern, aerodynamic trucks. The real difference between these estimates depends heavily on driving style and typical usage patterns.

Annual fuel cost

According to the EPA, the annual fuel cost for the 2019 GMC Sierra C10 2WD 5.3L is $2,600 per year. This figure is based on driving 15,000 miles annually, with 45% of those miles driven in the city and 55% on the highway. The calculation also assumes a national average fuel price, which can fluctuate depending on location and time of year. So be sure to compare the EPA figure to your own real-world spend. For owners who primarily use their Sierra for short commutes or heavy-duty work, the actual cost could easily exceed this estimate. Conversely, those who primarily use the truck for long highway trips may find their annual fuel expense to be somewhat lower.

Real-world expectations

While the EPA estimates provide a baseline, real-world fuel economy will vary based on several factors. Aggressive driving, including rapid acceleration and hard braking, can significantly reduce MPG. Towing or hauling heavy loads requires more power, further decreasing fuel efficiency. Terrain also plays a role; driving in hilly or mountainous areas demands more engine effort than driving on flat terrain.

Factors like tire pressure, vehicle maintenance, and even weather conditions can also subtly influence fuel economy. Keep up with your preventative maintenance to see the best numbers here; don’t expect 21 MPG on the highway if you need a tune-up.

How it compares

Compared to other full-size trucks of the same vintage, the 2019 Sierra C10 2WD 5.3L sits in a fairly typical spot. A comparable Ford F-150 with the 5.0L V8 and rear-wheel drive achieves roughly the same EPA estimates, around 17 MPG combined. However, newer trucks, even those with V8 engines, often boast better fuel economy due to advancements in engine technology, transmission design, and aerodynamics. A 2024 Silverado with a similar 5.3L V8 can nudge up to 18 or even 19 MPG combined. Those numbers represent a genuine improvement that costs extra on the showroom floor. For those cross-shopping within the GMC brand, browse SIERRA MPG across all years. For all Gmc fuel economy data, check out GMC’s fuel economy figures here.

Tips to maximize efficiency

Gentle acceleration is key. Avoid stomping on the gas pedal, especially when starting from a stop. Accelerate smoothly and gradually to minimize fuel consumption. The 5.3L V8 has plenty of torque, so you don’t need to floor it to get up to speed.

Maintain a steady speed on the highway. Use cruise control when appropriate to avoid unintentional speed fluctuations that can waste fuel. A higher, constant speed in excess of 70, however, will decrease fuel mileage dramatically due to this vehicle’s aerodynamics.

Keep your tires properly inflated. Underinflated tires increase rolling resistance, which forces the engine to work harder. Check your tire pressure regularly and inflate them to the recommended level. Consult the sticker on your driver’s side doorjamb for the correct PSI.

Minimize idling. If you’re going to be stopped for more than a minute, turn off the engine. Idling consumes fuel without moving the vehicle, which can significantly impact fuel economy, especially in city driving. This is particularly true for the 5.3L V8, which drinks fuel even at idle due to its larger displacement.

Reduce unnecessary weight. Remove any items from the truck bed that aren’t needed. Extra weight increases the engine’s workload and reduces fuel efficiency. Every pound saved contributes to less gas use over time. Consider removing tonneau covers or bed caps when not needed.