23 MPG combined is an acceptable, if unremarkable, figure for the 2015 Mercedes-Benz E400 Coupe. This isn’t a fuel-sipping hybrid; it’s a stylish two-door grand tourer with a potent turbocharged engine. Its buyers are prioritizing aesthetics, comfortable cruising, and a touch of performance over outright efficiency. They accept the fuel economy as a necessary trade-off for the style and driving experience this particular Mercedes delivers.

City and highway performance

The EPA estimates the E400 Coupe achieves 20 MPG in the city and 29 MPG on the highway. That 20 MPG city number reflects the realities of stop-and-go driving with a turbocharged engine. The 3.0L V6 needs a bit of throttle to get moving, especially when pulling away from a standstill. However, the 29 MPG highway figure shows the benefits of the seven-speed automatic transmission and relatively efficient engine when cruising at a steady speed. This car truly shines on longer journeys where it can settle into a relaxed rhythm.

Annual fuel cost

The EPA calculates that the average owner of a 2015 Mercedes-Benz E400 Coupe will spend $2,500 per year on fuel. This figure is based on driving 15,000 miles annually and using the national average fuel price at the time of the EPA’s testing. Keep in mind that fuel prices fluctuate considerably, and your actual costs may vary depending on your driving habits and where you live. This number provides a useful benchmark, allowing potential buyers to understand the ongoing running costs associated with owning the E400 Coupe.

Real-world expectations

While the EPA estimates provide a helpful baseline, real-world MPG can vary significantly. Aggressive driving habits, frequent short trips, and even tire pressure can all impact fuel economy. Expect to see numbers closer to the EPA ratings if you primarily drive on the highway and maintain a smooth, consistent driving style. In mixed driving conditions, achieving the combined 23 MPG figure is realistic, but don’t be surprised if it dips a bit lower, especially if you enjoy using the engine’s power on a regular basis. For drivers concerned with fuel consumption, monitoring your MPG via the car’s trip computer can provide valuable insights into your driving habits and their impact on efficiency.

How it compares

Compared to other luxury coupes of its era, the 2015 E400 Coupe occupies a middle ground in terms of fuel economy. The BMW 435i Coupe with its 3.0L turbocharged inline-six, for example, is rated at 25 MPG combined. The Infiniti Q60 with its 3.7L V6, offered similar performance but slightly lower fuel economy, usually around 22 MPG combined. For comparison across the Mercedes-Benz lineup, see all Mercedes Benz fuel economy data. The Audi A5 with its turbocharged 2.0L four-cylinder engine offered significantly better fuel economy at 26 MPG combined, but with a trade-off in terms of power and overall driving experience. Understanding these comparisons helps prospective buyers weigh performance against efficiency and determine which vehicle best aligns with their priorities. See this particular model’s E400 MPG across all years data, which shows consistency in its fuel consumption profile.

Tips to maximize efficiency

The E400 Coupe’s turbocharged engine is sensitive to driving style. Avoiding hard acceleration and maintaining a steady speed will significantly improve fuel economy. The engine management system injects additional fuel during rapid acceleration, so easing onto the throttle will help you stay in a more efficient operating range.

Ensure your tires are properly inflated. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Check your tire pressure regularly and inflate them to the manufacturer’s recommended specifications, typically found on a sticker in the driver’s side doorjamb.

Minimize idling. Letting the engine idle for extended periods wastes fuel. If you’re stopped for more than a minute, it’s generally more efficient to turn off the engine and restart it. This is especially true with modern engines like the E400’s, which are designed to start quickly and efficiently.

Use cruise control on long highway drives. Cruise control helps maintain a consistent speed, minimizing unnecessary acceleration and deceleration. This can lead to noticeable improvements in fuel economy, especially on relatively flat stretches of road. Remember to disengage cruise control when approaching hills or changing traffic conditions.

Keep the car properly maintained. Regular maintenance, including oil changes and air filter replacements, ensures the engine is running at its optimal efficiency. A dirty air filter, for example, can restrict airflow and reduce fuel economy, negating some of the efficiency gains the engine is designed to provide.