The 2021 Mercedes-Benz E450 4matic Convertible, with its combined EPA rating of 25 MPG, isn’t trying to be a fuel-sipper. It offers open-air thrills and effortless cruising, a blend of luxury and performance that defines a grand tourer. This isn’t a commuter car; it’s a statement, a vehicle for weekend getaways and sun-drenched cruises along the coast, with fuel economy that reflects that focus.

City and highway performance

The EPA estimates for the E450 Convertible are 23 MPG in the city and 29 MPG on the highway. The city figure is respectable given the car’s weight and the demands of stop-and-go driving. The 29 MPG highway rating shows how efficient the 3.0L inline-six engine and 9-speed automatic transmission can be on the open road. The difference between city & highway MPG isn’t huge, suggesting the engine is well-suited to both environments. Drivers spending a significant amount of time on open roads will likely see numbers closer to the EPA highway estimate.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2021 Mercedes-Benz E450 4matic Convertible is $2,300. This is based on driving 15,000 miles per year and using national average fuel prices. Individual costs will vary depending on driving habits, local fuel prices, and the grade of gasoline used. Instead of regular fuel, premium fuel is recommended for optimal performance in the E450, which will increase your costs.

Real-world expectations

While the EPA provides a standardized benchmark, real-world fuel economy often differs. Aggressive driving, frequent short trips, and extended idling can negatively impact fuel consumption. However, drivers who accelerate smoothly, maintain a steady speed on the highway, and properly maintain their vehicle may exceed the EPA estimates. The E450’s 4MATIC all-wheel-drive system enhances traction and stability, but it also adds weight, which can slightly reduce fuel economy compared to a rear-wheel-drive variant.

How it compares

The BMW 440i Convertible has a similar goal, offering performance and open-air enjoyment. Its MPG figures are similar, around 23 MPG combined. The Audi S5 Cabriolet, with its turbocharged V6, also competes, and its fuel economy is close to 24 MPG combined. The Lexus LC 500 Convertible is for someone interested in a naturally aspirated V8, and its roughly 19 MPG combined reflects its different priorities. For those looking to explore all Mercedes Benz fuel economy data, there are more frugal choices within the brand. Someone weighing fuel costs might also examine the E450 MPG across all years to understand long-term trends.

Tips to maximize efficiency

Use the E450’s drive modes. Selecting “Comfort” or “Eco” will optimize the engine and transmission for fuel efficiency by softening throttle response and encouraging earlier upshifts. These modes directly alter the car’s behavior.

Ensure proper tire inflation. Maintaining the recommended tire pressure reduces rolling resistance, which improves fuel economy. The E450’s tire pressure monitoring system makes it easy to monitor this.

Avoid unnecessary weight. Remove any non-essential items from the trunk or rear seats. Excess weight increases the engine’s workload and negatively impacts fuel consumption.

Plan your trips strategically. Combining errands into a single trip minimizes cold starts, which are less fuel-efficient than driving a warmed-up engine. The E450’s navigation system can help optimize routes to avoid traffic.

Consider the fuel you use. Premium fuel is recommended, and using a high-quality brand may make a difference. Also, make sure you buy your gas from a reputable location to avoid lower quality fuel.