23 MPG combined isn’t going to win the 2016 Mercedes-Benz E400 Convertible any fuel economy awards, but that figure alone misses the point. This isn’t a car for hypermilers; it’s for those who prioritize open-air elegance and effortless power. The E400 Convertible is designed to deliver a visceral driving experience, a blend of luxury and performance that asks for compromises. For its target audience, a mid-20s combined MPG rating is a price they’re willing to pay for the prestige and enjoyment this vehicle provides.

City and highway performance

The official EPA estimates peg the E400 Convertible at 20 MPG in the city and 29 MPG on the highway. The city figure reflects the stop-and-go conditions that often impact fuel efficiency, where the 3.0L V6 engine needs more fuel to get moving. The highway number, on the other hand, showcases the engine’s relaxed cruising ability at higher speeds. The seven-speed automatic transmission helps optimize fuel economy on the open road, keeping the engine in its sweet spot while delivering smooth power delivery and quick response with the paddle shifters.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2016 Mercedes-Benz E400 Convertible at exactly $2,500. This calculation is based on driving 15,000 miles per year, with a mix of city and highway driving, using the national average fuel price at the time of the EPA’s testing. The actual cost of fuel will depend on individual driving habits, local fuel prices, and the blend of city versus highway miles covered. The $2,500 figure serves as a benchmark for potential owners to consider its operational cost against its appealing ownership experience.

Real-world expectations

While the EPA provides standardized fuel economy figures, real-world driving conditions can vary considerably. Expect slightly lower numbers if you frequently engage in spirited driving with heavy acceleration, driving in congested city traffic, or driving in extreme weather conditions, whether hot or cold. Conversely, consistent highway driving at moderate speeds with minimal traffic could yield MPG figures close to or even slightly above the EPA’s 29 MPG estimate. How you drive the E400, and where you drive it, will significantly impact your fuel consumption.

How it compares

The 2016 BMW 435i Convertible, a direct competitor, achieves a slightly better 25 MPG combined. The Audi A5 Cabriolet, equipped with a four-cylinder engine, boasts around 27 MPG combined. These differences are often negligible for buyers in this segment, who are more concerned with styling, performance, and brand cachet. The E400’s V6 delivers significantly more punch than the A5’s four-cylinder, justifying the fuel economy difference for those prioritizing power. You can find all Mercedes Benz fuel economy data including the E400 MPG across all years on our website.

Tips to maximize efficiency

Adopt a smooth and progressive driving style. Avoid aggressive acceleration and hard braking, as these actions consume significantly more fuel. Anticipate traffic flow and maintain a steady speed whenever possible. The E400’s reliable torque means you don’t need to push the engine hard to achieve brisk acceleration.

Regularly maintain your E400 Convertible according to the manufacturer’s recommendations. This includes ensuring proper tire inflation, changing the engine oil and air filter at specified intervals, and keeping the engine properly tuned. A well-maintained engine operates more efficiently, thereby improving fuel economy.

Minimize the use of accessories that place a significant load on the engine, such as air conditioning, especially when driving at lower speeds. While the E400’s automatic climate control is very precise, consider lowering the top when weather permits. Driving with the top down can significantly reduce the need for air conditioning, improving fuel efficiency while enjoying the open-air experience.

Use the cruise control on the highway to maintain a consistent speed and optimize fuel consumption. Cruise control can help prevent unnecessary acceleration and deceleration, leading to improved MPG. However, avoid using cruise control in hilly terrain or heavy traffic, where it may not be as effective.

Plan your routes carefully to avoid congested areas and unnecessary stops. Opt for routes that allow for more consistent speeds and fewer traffic jams. Even short periods of idling can negatively impact fuel economy, so minimizing idling time is an important step in maximizing efficiency. Use navigation apps to identify and avoid traffic bottlenecks.