24 MPG combined is not the main reason someone buys a 2022 Mercedes-Benz C300 Convertible. If ultimate fuel efficiency topped the priority list, this particular model would never make the short list. This is a vehicle designed for style, open-air enjoyment, and a certain level of panache. Fuel consumption, while certainly considered, plays a supporting role rather than a starring one. This vehicle is bought with emotion as much as logic.

City and highway performance

The C300 Convertible equipped with its 2.0L turbocharged 4-cylinder engine and 9-speed automatic transmission achieves 21 MPG in the city and 28 MPG on the highway, according to EPA estimates. This split reflects the engine’s responsiveness and the transmission’s ability to keep the engine in its optimal power band. The city figure, while not stellar, is adequate for urban cruising, while the highway number allows for comfortable and relatively efficient long-distance drives. Remember that these figures are based on laboratory testing and may not perfectly reflect real-world driving conditions. Aggressive acceleration and higher speeds will invariably lead to lower MPG figures, especially with this engine which encourages spirited driving.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2022 Mercedes-Benz C300 Convertible at $2,400. This figure assumes 15,000 miles driven per year, with fuel prices based on the national average. It provides a useful benchmark for comparing the fuel costs of different vehicles, but individual spending will depend on unique driving habits and local fuel prices. If you drive fewer miles, or if fuel costs are lower in your area, your actual annual expenditures will be less; if you drive more or fuel is more expensive, you will spend more. The figure is a starting point, not a guarantee.

Real-world expectations

While the EPA provides a standardized estimate, real-world MPG will naturally vary based on individual driving styles and environments as well as regular maintenance. Expect numbers closer to the low 20s if you spend most of your time in stop-and-go city traffic, and potentially higher than 28 MPG on long highway trips if you maintain a steady speed. Variables like tire pressure, proper maintenance, and the use of air conditioning can also impact fuel consumption. Consistent full-throttle acceleration will have a demonstrably negative impact, and the C300’s engine is willing to provide all the temptation necessary to abuse it. But with careful driving, it’s possible to get closer to the advertised numbers.

How it compares

Compared to competitors, the C300 Convertible’s fuel economy is within the expected range for its class. The BMW 430i Convertible achieves a similar 24 MPG combined, but slightly favors highway driving with 25 MPG city and 34 MPG highway. The Audi A5 Cabriolet, another key rival, lands at 27 MPG combined. These differences, while seemingly small, can add up over time. But the typical buyer in this segment places just as much, if not more, emphasis on factors like styling, brand image, and features. If maximizing efficiency tops the list, the fuel economy of the C300 is somewhat of a compromise, but one most buyers weighing an open-top Benz are willing to make, especially given the performance of its eager engine.

Tips to maximize efficiency

The 9-speed automatic transmission is designed to keep the engine in its most efficient range, so avoid aggressive acceleration to allow the transmission to shift smoothly and early. Anticipate traffic flow to minimize unnecessary braking and acceleration. A smoother driving style will produce the greatest fuel savings.

Check your tire pressure regularly. Underinflated tires increase rolling resistance, which directly impacts fuel economy. Refer to the sticker on the driver’s side doorjamb for the recommended tire pressure, and ensure your tires are properly inflated, especially during colder months when tire pressure tends to drop.

Reduce unnecessary weight in the vehicle. Carrying around extra cargo not only puts more strain on the engine, but also detracts from the overall driving experience. Remove items when they are not needed to maximize efficiency and to open up valuable space.

Consider using cruise control on long highway drives. Maintaining a constant speed helps reduce variations in fuel consumption. Cruise control is particularly effective on relatively flat terrain, but avoid using it in hilly areas or during heavy traffic, as it can sometimes lead to inefficient gear changes.

Regular maintenance is important to fuel economy. Ensure your car is properly maintained, with timely oil changes, air filter replacements, and spark plug replacements. A well-maintained engine operates more efficiently, which translates to better fuel mileage. You can review C300 MPG across all years.

For more information about Mercedes-Benz fuel efficiency, see all Mercedes Benz fuel economy data.