20 MPG combined won’t win any awards, but the 2016 GMC Sierra C15 2WD with the 4.3L V6 is a work truck first. It’s not for hypermiling; it’s for reliably and affordably getting the job done. For contractors, small business owners, and fleet operators, the V6 Sierra is a calculated compromise: enough power to haul and tow, with reasonable fuel consumption that keeps running costs in check. Fuel efficiency is only one part of the purchase equation, and they accept this fuel economy because it’s a tool.

City and highway performance

The EPA estimates provide a breakdown of fuel economy for different driving conditions. The city rating is 18 MPG, reflecting urban stop-and-go driving. The V6 works harder to accelerate from a standstill, so expect higher fuel use.

On the open road, the Sierra V6 is more relaxed, and the EPA highway rating of 23 MPG is more achievable when cruising on interstate roads. The 6-speed automatic transmission helps the engine settle into a lower RPM range to optimize efficiency at higher speeds. These figures are for a rear-wheel-drive model; adding four-wheel drive will decrease them.

Annual fuel cost

The EPA estimates that the annual fuel cost for the 2016 GMC Sierra C15 2WD 4.3L 6-cyl is $2,200. This is based on driving 15,000 miles per year and using national average fuel prices. Your actual fuel costs will vary depending on your driving habits, road types, and gasoline prices in your area. Aggressive driving, frequent towing, and extended idling will all increase fuel consumption and push the annual cost higher. This $2,200 figure is a useful benchmark, but tailor your expectations to your specific usage patterns.

Real-world expectations

EPA estimates provide a standardized benchmark, but real-world fuel economy can differ significantly. Many owners report that their actual mileage falls within a reasonable range of the EPA estimates, though consistently hitting the exact figures can be challenging.

Driving style, load weight, tire pressure, and weather conditions influence fuel efficiency. Achieving the rated 23 MPG on the highway is realistic if you maintain a steady speed and avoid aggressive acceleration with the V6 Sierra. City driving tends to be more variable. Careful driving habits influence whether you see the EPA rated numbers.

How it compares

The 2016 Sierra V6 stacks up well against its contemporaries, especially considering its utility. For example, the 2016 Ford F-150 with its base 3.5L V6 offers similar fuel economy numbers depending on configuration. A comparable Ram 1500 V6 also lands in the same ballpark. Choosing between them often comes down to brand preference, styling, and specific feature requirements rather than focusing almost exclusively on fuel savings. The Sierra’s V6 offers a combination of capability and cost-effectiveness. The SIERRA MPG across all years shows a consistent trend: the V6 balances practicality with acceptable operating expenses, making it a sensible choice for those who need a truck but don’t require V8 power.

Tips to maximize efficiency

One of the most effective ways to improve fuel economy in the Sierra V6 is to adopt a smoother, more relaxed driving style. Avoid hard acceleration and braking, and maintain a consistent speed when possible. The 6-speed automatic is programmed for efficiency; let it do its job. Heavy throttle inputs will immediately trigger downshifts and increased fuel consumption.

Regular maintenance is important for optimizing fuel efficiency. Ensure that your tires are properly inflated to the recommended pressure. Low tire pressure increases rolling resistance, reducing fuel economy. Also, keep up with scheduled oil changes and air filter replacements to help your engine run more efficiently.

Minimize idling time. Letting the engine idle for extended periods wastes fuel, especially in city environments. Turn off the engine if you anticipate being stationary for more than a minute or two; it’s more efficient to restart it when you’re ready to go.

When hauling cargo or towing a trailer, remember that added weight significantly impacts fuel economy. Distribute the load evenly and avoid exceeding the vehicle’s maximum payload or towing capacity. Remove any unnecessary weight from the truck bed or cab to improve efficiency when not actively using the truck for work.