19 MPG combined isn’t setting any fuel-sipping records, especially in 2024, but the BMW M850i xDrive Convertible isn’t designed for saving gas. This is a grand touring convertible, a statement of personal arrival that prioritizes a thundering V8 and open-air exhilaration over minimizing trips to the gas station. The target customer isn’t looking for efficiency; they’re looking for a visceral driving experience wrapped in luxurious appointments, and they’re willing to pay for it, both at the dealership and at the pump.

City and highway performance

The EPA estimates the M850i xDrive Convertible achieves 17 MPG in the city and 24 MPG on the highway. The lower city figure reflects the engine’s thirst during stop-and-go traffic, where the 4.4L twin-turbo V8 is constantly tasked with propelling the car’s considerable weight from a standstill. The highway number, while still not exceptional, benefits from the engine operating at a more consistent speed, using the transmission’s higher gears to reduce fuel consumption. However, even on the open road, the temptation to exploit the engine’s prodigious power output will invariably lead to a lower actual MPG.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2024 BMW M850i xDrive Convertible at $3,050. This figure is based on driving 15,000 miles per year and using the EPA’s estimated combined fuel economy of 19 MPG. It further assumes current national average fuel prices. If you drive more than 15,000 miles annually or live in an area with higher-than-average fuel costs, your actual fuel expenses will likely exceed $3,050, potentially by a substantial margin. This expense is simply part of the ownership experience for a high-performance luxury vehicle.

Real-world expectations

While the EPA provides a standardized benchmark, real-world fuel economy often deviates. Owners of the M850i xDrive Convertible should anticipate seeing figures slightly below the EPA estimates, particularly if they frequently drive hard or operate primarily in urban environments. Aggressive acceleration, frequent braking, and idling in traffic all contribute to decreased fuel efficiency.

On the other hand, those who consistently drive with a light foot on the accelerator and prioritize highway cruising may achieve MPG closer to the EPA’s projections. Understanding your own driving habits is critical to managing fuel costs.

How it compares

The M850i xDrive Convertible’s fuel economy is similar to its competition. The Mercedes-AMG SL 55, another high-performance luxury convertible, delivers a similar 16 MPG city and 24 MPG highway. An Audi S5 Cabriolet, with its smaller engine, achieves a more respectable 21 MPG combined, but lacks the raw power and prestige of the BMW. Even the Porsche 911 Carrera Cabriolet, often lauded for its relative efficiency, only manages around 20 MPG combined in real-world driving, depending on the specific configuration. These comparisons show that the M850i’s fuel consumption is normal for a vehicle in this class, and is perhaps a secondary consideration for those drawn to its performance and style. See all Bmw fuel economy data available.

Tips to maximize efficiency

While prioritizing fuel economy might seem counterintuitive for an M850i owner, there are still steps that can be taken to minimize fuel consumption without sacrificing driving enjoyment. Avoid excessively aggressive acceleration and braking. The M850i’s immense power can be addictive, but smooth, gradual inputs will significantly improve fuel efficiency.

Use the car’s driving modes effectively. The “Eco Pro” mode optimizes various vehicle systems for maximum fuel efficiency, including throttle response and shift patterns. While it may slightly reduce performance, it can make a noticeable difference on longer journeys.

Ensure proper tire inflation. Underinflated tires increase rolling resistance, leading to decreased fuel economy. Regularly check and maintain the tires at the recommended pressure listed on the doorjamb, and consider the impact of warm weather on tire pressure.

Minimize unnecessary weight. Carrying excessive cargo, such as golf clubs or luggage, adds weight and reduces fuel efficiency. Remove any unnecessary items from the trunk and rear seats to lighten the load.

Consider the route. Whenever possible, choose routes that avoid heavy traffic congestion. Stop-and-go traffic burns considerably more fuel than steady highway cruising. Strategic route planning can save both time and fuel. Check out M850I MPG across all years.