While the 2023 Mercedes-Benz C300 4matic Convertible gets 25 MPG combined, that’s likely not the main draw for buyers. People choosing a stylish, open-air luxury car probably aren’t making fuel consumption their top priority. They’re buying the experience: the wind in their hair, the prestige of the Mercedes-Benz badge, and the confidence that comes with a well-engineered machine. But 25 MPG isn’t bad, and for the power and persona on offer, it’s an acceptable compromise.

City and highway performance

The EPA estimates the C300 Convertible gets 21 MPG in the city and 30 MPG on the highway. As with most vehicles, the city MPG suffers from stop-and-go traffic and the engine working harder to accelerate from a standstill. The 30 MPG highway number is much better, reflecting the car’s ability to cruise easily at speed. The 9-speed automatic transmission helps, keeping the engine in its optimal range for both power delivery and efficiency.

Since many C300 Convertible owners use their cars for weekend trips and top-down excursions, the highway MPG is arguably more relevant than the city figure.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2023 Mercedes-Benz C300 4matic Convertible at $2,300. This is based on driving 15,000 miles per year and using national average fuel prices. It’s a useful benchmark, but your actual fuel costs will vary.

If you primarily drive in the city, rack up more miles than average, or regularly drive aggressively, you can expect to spend more. If you do mostly highway driving and practice efficient driving habits, you could spend less. Consider this a starting point for budgeting, not a guarantee.

Real-world expectations

The EPA provides a standardized test, but real-world fuel economy often differs. Expect variations based on driving style, weather conditions, and even tire pressure. Aggressive driving, frequent hard acceleration, and neglecting maintenance will all negatively impact fuel efficiency.

Smooth acceleration, consistent speed while using cruise control, and keeping tires properly inflated can nudge you closer to the EPA estimates. Don’t be surprised if you see slightly lower-than-advertised numbers, especially if most of your driving is in congested areas.

How it compares

The C300 Convertible’s fuel economy positions it competitively. The BMW 430i Convertible, another popular choice, achieves approximately 28 MPG combined with its similar 2.0L turbocharged engine. The Audi A5 Cabriolet gets around 27 MPG combined. These differences can add up over time.

However, for buyers in this segment, a few MPG rarely sways the decision. The decision more likely hinges on styling, brand preference, and features rather than a strict MPG comparison. If maximizing efficiency is a top priority, there are greener vehicle choices. Check all Mercedes Benz fuel economy data to see full brand comparisons, and C300 MPG across all years.

Tips to maximize efficiency

Take advantage of the C300’s drive modes. The “Comfort” mode prioritizes fuel efficiency by optimizing throttle response and shift points. “Sport” mode is more engaging, but it sacrifices fuel economy for quicker acceleration.

Avoid unnecessary idling. The C300 has an automatic start/stop system that shuts off the engine at stoplights and extended idle situations. Ensure this feature is enabled to further boost fuel savings, particularly in city driving.

Maintain proper tire inflation. Underinflated tires increase rolling resistance, which reduces fuel efficiency. Check your tire pressure regularly and inflate them to the recommended specifications listed on the driver’s side doorjamb or in the owner’s manual.

Practice smooth and steady driving. Avoid aggressive acceleration and hard braking, as these habits consume more gas. Anticipating traffic flow and maintaining a consistent speed will improve fuel economy and contribute to a more relaxed driving experience.

Keep up with scheduled maintenance. Regular oil changes, air filter replacements, and spark plug maintenance ensure that the engine runs optimally, maximizing fuel efficiency and extending its lifespan. Follow Mercedes-Benz’ recommended maintenance schedule.