24 MPG combined isn’t going to win any hypermiling contests, but fuel economy isn’t the main reason someone buys a 2023 Mercedes-Benz E450 4matic Convertible. This car is made for enjoying the sun, the sound of a refined inline-six engine, and envious glances as you cruise. Lower fuel costs matter, of course, but they are secondary to open-air luxury and effortless performance.

City and highway performance

The EPA estimates of 22 MPG in the city and 29 MPG on the highway reflect the E450’s engine and its typical driving. The city number is influenced by stop-and-go traffic where the car’s weight and engine size become apparent. The 29 MPG highway number is more impressive. The 9-speed automatic transmission helps keep the engine at optimal cruising RPM, maximizing efficiency while providing power for passing. You can expect to achieve the EPA highway figure if you’re gentle with the throttle on longer trips.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2023 Mercedes-Benz E450 4matic Convertible is $2,400 per year. This is based on driving 15,000 miles annually and using national average fuel prices as determined by the EPA. The actual cost will vary depending on driving habits, local fuel prices, and the type of fuel used. $2,400 is a significant amount, but it’s a cost many E450 owners are willing to bear for the privilege of driving such an enjoyable vehicle. They are purchasing an experience as much as transportation.

Real-world expectations

Real-world fuel economy can vary. Aggressive driving, frequent acceleration, and consistent short trips will negatively impact fuel consumption, pushing the average MPG below the EPA estimates. However, gentle acceleration, anticipation of traffic flow, and longer highway drives may allow owners to exceed the EPA’s 29 MPG highway rating. Consider downloading a fuel tracking app to monitor your individual fuel economy and identify ways to improve your driving.

How it compares

The E450’s fuel economy is competitive. Direct comparisons are important for buyers. For example, the BMW 440i Convertible achieves roughly similar MPG. The Audi S5 Cabriolet posts EPA numbers in the same ballpark as the E450. The slightly smaller Lexus RC 350 Convertible trails slightly at 23 MPG combined.

None of these competitors offer a vastly superior fuel economy, so the purchasing decision often comes down to styling, brand loyalty, and driving. For a broader look at the brand’s fuel efficiency, see all Mercedes Benz fuel economy data. You can also compare across trim levels on our E450 MPG across all years page.

Tips to maximize efficiency

Take advantage of the E450’s “Comfort” driving mode. This setting optimizes throttle response and shift points for maximum fuel efficiency. The “Sport” and “Sport+” modes increase fuel consumption by holding gears longer and providing a more aggressive throttle map.

Ensure your tires are properly inflated. Underinflated tires increase rolling resistance, forcing the engine to work harder. Check your tire pressure regularly and inflate them to the recommended levels listed on the driver’s side door jamb label.

Avoid unnecessary idling. If you’re stopped for more than a minute, turn off the engine. Modern engines are designed to restart quickly and efficiently. The fuel saved by turning off the engine during prolonged idling can add up.

Use cruise control on long highway drives. Maintaining a consistent speed minimizes unnecessary acceleration and deceleration, helping fuel economy. Be mindful of traffic conditions and adjust your speed gradually.

Lighten your load. Remove any unnecessary items. Extra weight reduces fuel economy, so carrying only essential items can make a noticeable difference. An extra hundred pounds of golf clubs will impact fuel economy, especially in city driving.