25 MPG combined sets the 2026 Mercedes-Benz E450 4MATIC All-Terrain apart as a remarkably efficient luxury wagon, a pragmatic return for a long-roof that combines strong capability, genuine comfort, and an engine that provides effortless power delivery. This isn’t a vehicle bought for its outright efficiency to begin with, but rather for its unique blend of attributes: elegant design, spacious utility, and the understated confidence of 4MATIC all-wheel drive, all wrapped in the unmistakable Mercedes-Benz refinement. Buyers of the E450 All-Terrain are often individuals who appreciate the wagon’s practicality over an SUV’s bulk, valuing the lower center of gravity and more engaging driving dynamics without sacrificing passenger and cargo space. They prioritize long-distance comfort, premium materials, and the latest in safety and connectivity technology. The 25 MPG is a welcome bonus, mitigating the typical fuel economy concerns associated with a powerful, luxury European vehicle designed for diverse road conditions, including light off-road excursions.

City and highway performance

The EPA rates the E450 All-Terrain at 22 MPG in the city and an impressive 31 MPG on the highway. These figures highlight the engineering behind the 3.0L inline-six engine and its smooth integration with the 9-speed automatic transmission. The mild-hybrid system, incorporating an integrated starter-generator, plays a crucial role in achieving these numbers. In urban settings, the electric boost assists during acceleration, allowing the engine to operate more efficiently and facilitating smooth stop-start functionality that is virtually imperceptible. This smooth power delivery is precisely what owners expect, providing instant torque off the line while conserving fuel. On the open road, the tall ninth gear allows the powerful six-cylinder to cruise at remarkably low RPMs, significantly contributing to the 31 MPG highway rating. This is where the E450 All-Terrain truly shines, effortlessly dispatching miles with a calm demeanor, minimal engine noise, and impressive range. The vehicle’s aerodynamic profile, despite its wagon proportions and slightly increased ride height, also contributes to its commendable highway efficiency, allowing it to slip through the air with less resistance at legal cruising speeds.

Annual fuel cost

The EPA estimates an annual fuel cost of $2,300 for the 2026 Mercedes-Benz E450 4MATIC All-Terrain. This figure is calculated based on an average of 15,000 miles driven per year, assuming a mix of city and highway driving, and using national average fuel prices, which for premium gasoline are typically higher than regular. For the typical E450 All-Terrain owner, this annual expenditure integrates well into their overall cost of ownership. These are not buyers solely focused on the lowest possible fuel bill, but rather appreciate a predictable and manageable expense for a vehicle that delivers so much in terms of luxury, performance, and versatility. While $2,300 might seem substantial compared to a compact economy car, it’s a very reasonable amount for a German luxury vehicle with a reliable powertrain and extensive features. This cost is a minor consideration when weighed against the E450 All-Terrain’s initial purchase price and its overall value as a capable, and enduring family hauler or long-distance tourer.

Real-world expectations

In real-world driving, owners of the E450 All-Terrain can generally expect to meet or even slightly exceed the EPA’s combined 25 MPG, especially if their driving tends more towards highway cruising. The mild-hybrid system and the well-tuned powertrain are designed for consistent efficiency. Aggressive driving, frequent short trips without sufficient engine warm-up, and consistent use of the more dynamic driving modes will naturally see a slight dip from the official figures. Conversely, a driver who employs smooth acceleration, anticipates traffic, and uses cruise control on highways will find the E450 All-Terrain to be an impressively frugal machine for its class. The 3.0L inline-six, with its mild-hybrid assist, delivers its power so smoothly that it encourages a relaxed driving style, which inherently contributes to better fuel economy. And the intelligent 4MATIC system, while providing exceptional traction, is not a significant drain on fuel economy under normal driving conditions, only engaging the front wheels when necessary.

How it compares

The E450 All-Terrain occupies a niche, but it&#8217s one with strong rivals. Consider the 2026 Audi A6 Allroad, another premium German luxury wagon. The A6 Allroad, likely equipped with a similar mild-hybrid 3.0L V6, typically achieves around 24 MPG combined (e.g., the 2024 model is rated at 24 MPG combined with 21 City/28 Highway). Mercedes-Benz edges out its direct competitor here, highlighting the efficiency of its powertrain. For those considering an SUV alternative, the 2026 BMW X5 xDrive40i, with its 3.0L inline-six mild-hybrid, typically delivers around 23-24 MPG combined (the 2024 model gets 23 MPG combined with 21 City/27 Highway). The E450 All-Terrain, with its 25 MPG combined, offers a slight advantage while maintaining lower ride height and superior driving dynamics. Even the Volvo V90 Cross Country with its B6 powertrain and supercharged/turbocharged 2.0L four-cylinder setup typically manages about 24 MPG combined (e.g., the 2024 model gets 25 MPG combined with 22 City/29 Highway), putting it on par with the Mercedes despite having a smaller engine. The Mercedes-Benz E450 All-Terrain therefore stands out as a genuine leader in fuel efficiency within its specific segment of luxury off-road-capable wagons, offering more power and cylinders than some while still achieving competitive or superior MPG figures. For a detailed look at all Mercedes Benz fuel economy data, you can explore our comprehensive database. You can also find more information about E450 MPG across all years here.

Tips to maximize efficiency

Use the E450 All-Terrain’s various driving modes. “Eco” mode specifically optimizes powertrain response and climate control settings for maximum fuel savings. Use this mode during your daily commute or on long highway journeys to gently coax the best MPG from the turbocharged 3.0L engine with electric motor and its mild-hybrid system.

Maintain consistent tire pressure. The E450 All-Terrain is a substantial vehicle, and correctly inflated tires reduce rolling resistance, which directly impacts fuel economy. Check your tire pressure regularly, especially before long trips, to ensure they are at the manufacturer’s recommended levels.

Make the most of the mild-hybrid system’s coasting functionality. Under certain conditions, when you lift off the accelerator, the engine can shut off, and the vehicle will coast silently on electric power. Anticipate traffic and downhill sections, allowing the car to glide and save fuel.

Minimize unnecessary weight. While the E450 All-Terrain is designed for utility, routinely carrying heavy, unused items in the cargo area or on the roof rack can noticeably reduce fuel efficiency. Remove roof boxes or carriers when they are not in use.

Practice smooth acceleration and braking. The E450’s refined powertrain rewards a gentle driving style. Avoid jackrabbit starts and sudden stops, as aggressive driving forces the engine to work harder, consuming more fuel. The integrated starter-generator works most effectively with smooth inputs.