25 MPG combined isn’t going to impress hypermilers, but for the 2021 Mercedes-Benz E450 4matic Coupe, it’s an acceptable trade-off. This isn’t a car bought for saving fuel; it’s a statement vehicle, chosen for its sleek design, luxurious appointments, and confident performance. The E450 Coupe delivers a distinctly Mercedes driving experience, and while fuel economy might not be its defining characteristic, it’s also not a major drawback for its intended audience. Buyers prioritize style and comfort over outright efficiency, accepting this level of consumption as the price of entry into the exclusive coupe club, and the convenience of Mercedes-Benz’s 4matic all-wheel-drive system.

City and highway performance

The EPA estimates the E450 Coupe will achieve 23 MPG in the city and 30 MPG on the highway. The city figure reflects the stop-and-go nature of urban driving. The 3.0L inline-six engine benefits from Mercedes-Benz’s EQ Boost mild-hybrid system, which provides a small electric motor assist that helps smooth out acceleration and improve efficiency, particularly when starting from a standstill. On the open road, the E450’s 9-speed automatic transmission allows the engine to cruise at lower RPMs, contributing to the more favorable highway rating. Drivers can expect that highway number on long trips where conditions are favorable.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2021 Mercedes-Benz E450 4matic Coupe at $2,300. This figure assumes you drive 15,000 miles per year, with a roughly even split between city and highway driving, and fuel prices matching the current national average for premium gasoline, which the E450 requires. Individual fuel costs will vary depending on driving style, location, and local fuel prices. More aggressive driving, especially in Sport mode, will naturally increase fuel consumption and drive spending higher.

Real-world expectations

While the EPA provides a standardized benchmark, real-world fuel economy often varies. E450 Coupe drivers often report figures that are close to the EPA estimates. Achieving the quoted 30 MPG on the highway is possible when cruising steadily at legal speeds.

However, enthusiastic acceleration, frequent use of Sport mode, or persistent city driving with heavy traffic can easily lower average fuel economy. Owners who want better efficiency can use the car’s Eco mode, which optimizes throttle response and transmission behavior for fuel savings. Many owners will understand the importance of the 9-speed transmission, which helps the car achieve good fuel economy at higher speeds. Data from other Mercedes-Benz owners, and all Mercedes Benz fuel economy data, also reveals patterns across models and driving styles.

How it compares

The E450 Coupe exists in a segment where style and performance often outweigh fuel efficiency, but comparisons are relevant. The BMW 440i xDrive Coupe, for example, achieves an EPA-estimated 26 MPG combined from its turbocharged inline-six. The Audi S5 Coupe, with its turbocharged V6, offers a similar 24 MPG combined. These figures show that the E450’s fuel economy is competitive within its class, although other options offer slightly better ratings. However, the slight differences are often less important than other factors like design, technology, and brand preference, all of which play a significant role in the coupe-buying decision. You can also compare E450 MPG across all years to see how this model year compares.

Tips to maximize efficiency

Use the E450’s Eco mode. This driving mode softens throttle response and encourages earlier upshifts, reducing fuel consumption in everyday driving scenarios. It’s especially useful in stop-and-go traffic or when cruising on the highway.

Monitor tire pressure regularly. Underinflated tires increase rolling resistance, forcing the engine to work harder and burn more fuel. Keeping your tires properly inflated, as indicated on the door placard, improves fuel efficiency and extends tire life.

Avoid aggressive driving habits. Rapid acceleration and hard braking consume significantly more fuel. Smooth, deliberate acceleration and anticipating traffic flow can improve fuel economy considerably. A measured driving style is vital to good mileage for all Mercedes-Benz vehicles, including the E450.

Minimize idling. Idling for extended periods wastes fuel, especially with a larger engine like the E450’s. If you anticipate being stopped for more than a minute, turn off the engine to conserve fuel. The E450’s quick restart system makes this easy.

Reduce unnecessary weight. Carrying extra weight in the car decreases fuel efficiency. Remove any unnecessary items from the trunk or passenger area to lighten the load, improving fuel economy, especially during city driving.