19 MPG combined won’t win any awards, but for a fast grand tourer like the 2025 BMW M850i xDrive Gran Coupe, it’s an acceptable compromise. This isn’t a Prius; it’s a statement. The M850i Gran Coupe buyer wants performance, luxury, and presence. Fuel economy is less important than the thrill of the 4.4L twin-turbo V8.

City and highway performance

The EPA estimates 17 MPG in the city for the M850i xDrive Gran Coupe. Stop-and-go traffic and using the engine’s low-end torque will take their toll. On the open road, the rating improves somewhat, to 24 MPG on the highway. While 24 MPG isn’t stellar, it’s adequate for long-distance cruising, allowing reasonably sized gaps between fuel stops. The eight-speed automatic transmission is programmed for responsiveness and efficiency. The transmission makes the most of the engine’s broad powerband, contributing to acceptable efficiency on the highway. Aggressive driving will bring that number down quickly because this V8 responds eagerly to throttle inputs.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2025 BMW M850i xDrive Gran Coupe at $3,050. This is based on driving 15,000 miles per year, with 55% of those miles driven in the city and 45% on the highway. It also assumes national average fuel prices. Of course, if premium fuel prices rise (and they often do), or if you drive more aggressively than the EPA testing cycle simulates, expect that number to climb. This is a significant expense, and potential buyers should be aware of it.

Real-world expectations

The EPA estimates are a useful starting point, but real-world fuel economy will vary depending on driving style, traffic conditions, and even the local climate. Expect numbers slightly below the EPA estimates if you frequently find yourself in heavy traffic or enjoy using the M850i’s performance. Conversely, consistent highway driving at moderate speeds might yield MPG figures slightly *above* the EPA’s 24 MPG rating. The car’s computer monitors fuel economy, so you can track your driving habits and adjust accordingly.

How it compares

The M850i xDrive Gran Coupe’s fuel economy is similar to its competitors in the segment. The Mercedes-AMG CLS 53 achieves a slightly better 21 MPG combined. However, that car uses a smaller, less powerful inline-six engine. The Porsche Panamera 4S, also a competitor, achieves around 21 MPG combined. These numbers highlight the trade-off in choosing a high-performance four-door coupe: efficiency is secondary to power and driving dynamics. The M850I MPG across all years reflects this. Even other BMW models, like the X6 M60i with the same engine, achieve similar fuel economy, illustrating that this powertrain values output over maximizing MPG. All Bmw fuel economy data shows a focus on balancing performance and efficiency, with models like the M850i favoring the former.

Tips to maximize efficiency

Use the car’s drive mode selector carefully. “Eco Pro” mode will remap the throttle response, optimize shift points, and adjust the climate control system to prioritize fuel efficiency. It won’t transform the M850i into a hypermiler, but it can make a noticeable difference in everyday driving.

Maintain proper tire inflation. Underinflated tires increase rolling resistance, which impacts fuel economy. Check your tire pressures regularly and ensure they are at the recommended levels (found on the driver’s side doorjamb).

Anticipate traffic flow and avoid unnecessary braking and acceleration. Smooth driving is efficient driving. Look ahead, maintain a consistent speed whenever possible, and avoid sudden bursts of acceleration.

Minimize excessive idling. If you’re stopped for more than a minute or two, consider turning off the engine. Modern cars are designed to restart quickly and efficiently, and prolonged idling wastes fuel.

Consider using cruise control on the highway. Maintaining a constant speed minimizes throttle fluctuations, which can improve fuel economy on long journeys. Be cautious when using cruise control in hilly terrain, as the system may downshift aggressively to maintain speed, potentially negating fuel savings.