17 MPG combined. That figure, delivered by the 2023 GMC Sierra 1500 4WD with mud-terrain tires and the 2.7L turbocharged four-cylinder engine, isn’t going to win any hypermiling contests. But let’s be honest about who buys this particular iteration of the Sierra: it’s not someone prioritizing Prius-level fuel efficiency, it’s someone who needs a capable truck, appreciates the rugged aesthetic of those aggressive tires, and wants the relative affordability of the turbo-four without sacrificing four-wheel drive. For *that* buyer, 17 MPG is simply the price of admission.

City and highway performance

The EPA estimates this Sierra at 17 MPG in city driving and 18 MPG on the highway. This seeming parity highlights the driving style this truck is designed for. Stop-and-go city traffic often negates the benefits of the highway’s more consistent speeds, especially when factoring in the extra rolling resistance of the mud-terrain tires. The 2.7L turbo engine provides ample low-end torque for navigating urban environments, but that power comes at the expense of efficiency. On the highway, maintaining higher speeds with those tires also works the engine harder. The 8-speed automatic transmission tries to optimize efficiency, but ultimately the laws of physics, and the demands of those gnarly tires, prevail.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for this specific Sierra configuration is $2,600. This figure is based on driving 15,000 miles per year and using national average fuel prices. Keep in mind that this is just an estimate. If you drive significantly more or less than 15,000 miles annually, or if fuel prices in your area are dramatically higher or lower than the national average, your actual fuel costs will vary accordingly. Aggressive driving habits will also increase fuel consumption. The $2,600 figure provides a useful baseline, but you should personalize your expectations based on your own driving patterns and local fuel costs.

Real-world expectations

While the EPA provides a standardized testing methodology, real-world fuel economy often differs. You can expect to see numbers slightly below, or occasionally slightly above, the EPA ratings depending on your driving style, the terrain you typically encounter, and even weather conditions. Headwinds, for example, can significantly impact fuel efficiency, and hauling cargo or towing a trailer can also change fuel economy. Consistently driving with a light foot and adhering to posted speed limits will help you get closer to the EPA estimates; however, aggressive acceleration and frequent hard braking will quickly send your MPG plummeting.

How it compares

The 2023 Ford F-150 with the 2.7L EcoBoost V6 and four-wheel drive achieves a slightly better 20 MPG combined. The Ram 1500 with the eTorque 3.6L V6 and 4×4 manages around 21 MPG combined. Even the Chevy Silverado 1500, mechanically very similar to the Sierra, can achieve slightly better numbers, around 18 MPG combined, in configurations without the mud-terrain tires. So why choose the Sierra with this engine and tire combination? The answer again comes down to prioritization. The F-150 or Ram may offer slightly better fuel economy, but the Sierra’s styling, interior appointments, or specific feature availability might outweigh that difference for some buyers. The aggressive look matters to this buyer, and they are prepared reduce their SIERRA MPG across all years for the increased off-road ability. Ultimately, it’s about accepting a specific compromise.

Tips to maximize efficiency

First, ditch the lead foot. The turbocharged engine responds quickly to throttle inputs, but avoid excessive acceleration and hard braking. Smooth, gradual acceleration will significantly improve your fuel efficiency, especially in stop-and-go city driving.

Minimize idling. Modern engines are designed to operate efficiently even when cold, so prolonged idling is largely unnecessary and wastes fuel. If you’re going to be stopped for more than a minute, it’s generally more efficient to turn off the engine.

Keep your tires properly inflated. Check your tire pressure regularly and maintain the recommended inflation levels found on the sticker inside your driver’s side door. Under-inflated tires increase rolling resistance and decrease fuel economy, and the mud-terrain tires on this Sierra are already working against you.

Reduce unnecessary weight. Hauling around excessive cargo in the bed of the truck or in the cab adds weight, which in turn increases fuel consumption. Remove any unnecessary items to lighten the load and improve your MPG. This is particularly important for all Gmc fuel economy data because weight significantly affects full-size trucks.

Consider highway speeds. While those mud-terrain tires look great, they create significant drag at higher speeds. If you spend a lot of time on the highway, consider reducing speeds slightly. Every mile per hour over 60 can noticeably reduce fuel economy.