The 2018 Mercedes-Benz GLC300 4Matic achieves 24 MPG combined, a respectable figure for a compact luxury SUV, though not class-leading. Instead of maximizing fuel efficiency, this vehicle focuses on providing a premium experience and reliable all-weather capability. Buyers often accept this compromise for the prestige of the Mercedes-Benz brand and the GLC’s mix of comfort, technology, and available features. They appreciate the surefootedness of the 4Matic all-wheel-drive system and the generally solid feeling that the GLC provides.

City and highway performance

The GLC300’s 21 MPG city rating reflects typical stop-and-go driving conditions, where the 2.0L turbocharged four-cylinder engine has to work harder. If you spend most of your time idling or driving slowly through traffic, expect to see lower numbers. The GLC performs better on the open road, achieving 28 MPG in highway conditions. The nine-speed automatic transmission helps keep the engine operating efficiently at higher speeds, allowing for relaxed cruising and decent fuel mileage on longer trips. The combination of direct injection and turbocharging enables the small engine to provide sufficient power while achieving these fuel economy figures. For complete GLC300 MPG across all years, review the model history.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2018 Mercedes-Benz GLC300 4Matic at $2,400. This is based on driving 15,000 miles per year and using national average fuel prices. Remember that this is only an estimate. Your actual fuel costs will depend on your driving habits, the types of roads you drive on, and local fuel prices. Hard acceleration, frequent hard braking, and prolonged idling will all negatively impact your fuel consumption, increasing your annual fuel expenses significantly. Expect fuel prices to vary throughout the year.

Real-world expectations

While the EPA estimates offer a useful starting point, real-world fuel economy can vary depending on several factors specific to each driver. Driving style has a major impact; those who accelerate quickly will likely see lower MPG numbers. Terrain also matters, as hilly or mountainous areas will require more engine power, reducing efficiency. Weather conditions, such as strong winds or very cold temperatures, can also hurt fuel economy.

Regular maintenance is also critical. Underinflated tires, dirty air filters, and neglected oil changes can all reduce fuel efficiency.

How it compares

The GLC300’s fuel economy is competitive within the compact luxury SUV class, but it doesn’t lead the pack. For example, the 2018 BMW X3 xDrive30i, which also has a 2.0L turbocharged four-cylinder and all-wheel drive, gets a slightly better EPA-estimated 25 MPG combined. The Audi Q5 2.0T Quattro is another popular option and mirrors the GLC300’s 24 MPG combined. However, hybrid options like the Lexus NX 300h (31 MPG combined) or even plug-in hybrid choices like the Volvo XC60 T8 (27 MPG combined plus electric range) offer much better fuel economy if lower fuel costs is your priority. If you’re looking for all Mercedes Benz fuel economy data, be sure to check the ratings of each model and engine configuration.

Tips to maximize efficiency

Strategically Use the GLC300’s driving modes. The “Eco” mode changes the throttle response and transmission shift points to prioritize fuel efficiency. Though it may slightly reduce responsiveness, it can noticeably improve gas mileage on longer drives, especially on the highway. Use this mode whenever your primary goal is to maximize MPG.

Regularly check and maintain your tire pressure. Underinflated tires increase rolling resistance, making the engine work harder and burn more fuel. See the sticker on the driver’s side doorjamb for the recommended tire pressure and make sure your tires are properly inflated at least once a month. This simple step can noticeably impact fuel economy.

Avoid idling. While the GLC300’s engine is relatively small, idling still uses fuel. If you expect to be stopped for more than a minute or two, it’s generally more efficient to turn off the engine. Modern engines start quickly, so restarting the engine uses less fuel than idling for a long time.

Reduce weight. Carrying unnecessary weight in your GLC300 decreases fuel efficiency. Get rid of anything you don’t need regularly from the trunk or cargo area. Even small amounts of extra weight can add up and hurt your MPG over time.

Avoid aggressive driving. Rapid acceleration, hard braking, and high speeds all use more gas. Smooth and consistent driving is essential to maximize fuel efficiency. Anticipate traffic, keep a safe following distance, and avoid unnecessary acceleration or braking to improve your gas mileage.