20 MPG combined is what drivers can expect from the 2017 Mercedes-Benz E550 Convertible with its strong 4.7L V8. It’s not a vehicle bought for saving money on fuel; it’s bought for the experience of open-air motoring combined with easy power and luxury. The E550 Convertible appeals to a specific buyer: one who wants performance and prestige over fuel efficiency, and for whom the cost of fuel is less important than the experience this refined machine provides.

City and highway performance

The EPA estimates the E550 Convertible achieves 17 MPG in city driving and 25 MPG on the highway. The lower city number reflects the engine working harder to accelerate the heavier convertible through stop-and-go traffic, while the highway number benefits from steady-state cruising and the 7-speed automatic transmission’s ability to select higher gears for reduced engine RPM. However, expect these figures to drop if the V8’s ample power is frequently used, a temptation that’s hard to resist. The E550’s engine is designed to offer smooth acceleration and easy power at any speed, making it easy to push the throttle and watch the fuel gauge drop.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2017 Mercedes-Benz E550 Convertible to be $2,900. This figure is based on driving 15,000 miles per year and using the national average fuel price for premium unleaded gasoline, which the E550 requires. For owners covering significantly more annual mileage, especially in cities, the actual fuel cost could easily exceed this estimate. Anyone considering this vehicle should be prepared for a higher-than-average fuel bill compared to more fuel-efficient alternatives, given the price of premium gasoline.

Real-world expectations

The EPA provides a standard, but real-world fuel economy can change based on driving habits, traffic conditions, and terrain. Spirited driving, frequent acceleration, and extended idling will negatively impact fuel consumption. Conversely, smooth driving on flat terrain might yield figures closer to, or even slightly above, the EPA estimates. Owners who regularly use the E550’s performance capabilities should expect figures closer to the lower end of the EPA range, while those who primarily use the car for relaxed cruising might see slightly better results. Reviewing E550 MPG across all years can give prospective buyers more data.

How it compares

The E550’s fuel economy is similar to other V8-powered rivals in the luxury convertible class, but it doesn’t do as well as those with smaller, turbocharged engines. For example, the BMW 650i Convertible, with its 4.4L V8, offered similar MPG numbers. The Audi S5 Cabriolet, with its supercharged V6, achieves a slightly better 21 MPG combined. The S5 offers a different driving experience, focusing on handling and agility over the raw power of the E550’s V8. The differences are there. Buyers drawn to the E550 are typically less concerned with fuel efficiency and more interested in the effortless acceleration and refined character only a V8 can deliver. Drivers seeking maximum efficiency in a convertible may consider models like the BMW 428i Convertible, which achieves close to 27 MPG combined while providing less horsepower and torque. You can see all Mercedes Benz fuel economy data to put this particular vehicle in perspective.

Tips to maximize efficiency

The E550 Convertible isn’t designed for ultimate fuel efficiency, but some driving habits can help minimize fuel consumption. Avoid aggressive acceleration and braking, as they require significant bursts of power, leading to increased fuel usage, and try to drive smoothly, maintaining momentum and reducing fuel waste.

Ensure the tires are properly inflated to the recommended pressure. Underinflated tires increase rolling resistance, forcing the engine to work harder and burn more fuel. Regular tire pressure checks are a simple way to improve fuel economy.

Keep idling time to a minimum. Modern engines consume a surprising amount of fuel while idling, especially when cold. If you anticipate stopping for more than a few seconds, consider turning off the engine to save fuel. The E550 features premium materials that may not react kindly to extreme hot or cold ambient temperatures, so you’ll want to idle the engine long enough to get coolant flowing to sensitive rubber and plastic parts.

Use cruise control on the highway when you can. Maintaining a consistent speed helps optimize fuel consumption, as the engine doesn’t have to constantly adjust to changing speed. This is especially effective on relatively flat stretches of highway.