23 MPG combined is a respectable figure for the 2017 Mercedes-Benz E400 Coupe, especially when you consider what this car is: a stylish and luxurious two-door that prioritizes driving pleasure and curb appeal over outright fuel efficiency. This isn’t a car designed for hypermilers; it’s for those who appreciate a smooth, potent engine and a satisfying experience, and for whom fuel costs are secondary to the enjoyment of owning a Mercedes-Benz coupe.

City and highway performance

The EPA estimates for the E400 Coupe break down to 20 MPG in the city and 29 MPG on the highway. The city figure reflects stop-and-go driving, where the 3.0L turbocharged V6 works harder, and the automatic transmission cycles frequently. The highway MPG is considerably better, highlighting the engine’s efficiency at cruising speeds and the benefits of the 7-speed automatic, which allows the engine to run at lower RPMs. Drivers who frequently undertake longer journeys can expect fuel economy closer to the highway estimate, while those primarily driving in urban environments might find themselves closer to the 20 MPG city number. This variance is typical and aligns with real-world driving patterns.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for the 2017 Mercedes-Benz E400 Coupe is $2,500. This figure is based on driving 15,000 miles per year and using national average fuel prices. Remember that this is an estimate, and your actual fuel costs may vary depending on your driving habits, the type of fuel you use, and local fuel prices. Aggressive driving and premium fuel, for instance, would likely increase your annual fuel expenditure beyond the $2,500 mark. Of course, prices have changed significantly since then, and this would be very different today.

Real-world expectations

While the EPA provides a standardized benchmark, real-world fuel economy often deviates. The powerful V6 under the hood of the E400 is tempting to use, and enthusiastic drivers may find themselves dipping below the EPA estimates. On the other hand, drivers who prioritize smooth acceleration and anticipate traffic flow can often achieve figures closer to the EPA’s, or even slightly higher on long highway trips. Driving style is a critical factor, as is keeping up with regular maintenance, including tire inflation and oil changes, to ensure the engine runs optimally. Refer to all Mercedes Benz fuel economy data for more information.

How it compares

Compared to its competitors, the 2017 E400 Coupe’s fuel economy is within the expected range for its class. For example, the BMW 440i Coupe from the same year, with its 3.0L turbocharged inline-six, achieves a similar 21 MPG combined. The Audi A5 Coupe, with its smaller 2.0L turbocharged four-cylinder engine, boasts slightly better figures, around 25 MPG combined. The Lexus RC 350 offers comparable power, but its fuel economy is generally a bit lower, hovering around 22 MPG combined. The E400 Coupe buyer often accepts this level of fuel economy because they prioritize the smooth power delivery of a V6 over the absolute best MPG figures. They appreciate the E400’s blend of luxury, performance, and distinctive styling, and understand that those attributes come at a cost. Explore E400 MPG across all years for more insight.

Tips to maximize efficiency

Use the “Eco” driving mode whenever possible. This mode adjusts the engine and transmission settings to prioritize fuel efficiency. While it might slightly diminish the car’s responsiveness, it can noticeably improve your MPG, particularly in urban environments, and help offset the times you decide to engage “Sport” mode.

Monitor your tire pressure regularly. Underinflated tires increase rolling resistance, which directly impacts fuel economy. Refer to the sticker on the driver’s side doorjamb for the recommended tire pressure for your E400 and ensure all tires are properly inflated, using a reliable tire pressure gauge. A properly inflated tire also handles better, giving you a more secure driving experience.

Avoid aggressive acceleration and braking. Rapid acceleration consumes significantly more fuel than gradual acceleration. Anticipate traffic flow and maintain a consistent speed whenever possible. Avoid hard braking by anticipating stops and slowing down gradually. The E400 has very powerful brakes, but that doesn’t mean you should overuse them.

Minimize idling time. If you’re stopped for more than a minute or two, turn off the engine. Modern engines are designed to restart quickly and efficiently, and idling wastes fuel unnecessarily. This is particularly important in stop and go traffic because, even though the car is off, some auxiliary components are likely still pulling power.

Consider the grade of fuel. Premium fuel is often recommended for optimal performance in cars like the E400, but running mid-grade fuel might only slightly affect performance. Test both to assess if there is a considerable difference in real-world performance that is noticeable to your driving habits. If the performance is roughly the same, you might be able to save on fuel costs in the long run by not using premium.