BMW · 2023
M850i xDrive Convertible 4.4L 8-cyl
✓ EPA Verified
Premium Gasoline
Subcompact Cars
All-Wheel Drive
City
17
MPG
Combined
19
MPG
Highway
24
MPG
Annual Fuel Cost
$3,050
Based on 15,000 miles/year · EPA estimates
vs avg gas vehicle
$900
more per year
Class Comparison — Subcompact Cars
Bottom 11%
Better than 11 out of 100 vehicles in its class for fuel efficiency.
This vehicle: 19 MPG
This vehicle
19 MPG
Class average
27 MPG
Class lowest
12 MPG
EPA Energy & Environment Scores
4
Energy Score
Out of 10
4
GHG Score
Out of 10
457 lbs
Annual CO₂
g/mile tailpipe CO₂
Yes
Start-Stop
Auto stop-start
Vehicle Specifications
Engine4.4L 8-cyl
TransmissionAutomatic (S8)
DriveAll-Wheel Drive
Fuel TypePremium Gasoline
Vehicle ClassSubcompact Cars
Engine DescSIDI
Start-StopYes
EPA Vehicle ID45224

19 MPG combined. Let’s be honest, no one choosing a 2023 BMW M850i xDrive Convertible is prioritizing fuel efficiency. They’re prioritizing the thrill of a twin-turbocharged V8, the wind in their hair, and the envious stares of passersby. This car is an unapologetic statement of success and driving pleasure, where fuel economy takes a distant back seat to raw performance and opulent luxury.

City and highway performance

The M850i Convertible’s EPA estimates paint a picture of its likely consumption in typical driving scenarios. In the city, the big V8 gets 17 MPG. Stop-and-go traffic and frequent acceleration will keep the turbos spooled and the fuel flowing. Out on the open road, things improve, with a highway rating of 24 MPG. This suggests that longer cruises at consistent speeds allow the engine to operate more efficiently, though even then, the temptation to exploit the readily available power will inevitably impact your mileage. The automatic (S8) transmission is tuned for both performance and relative efficiency, but its primary objective is smooth power delivery, not maximizing fuel savings.

Annual fuel cost

The EPA estimates that a driver of the 2023 BMW M850i xDrive Convertible will spend approximately $3,050 on fuel annually. This figure is based on driving 15,000 miles per year, with an assumed percentage split between city and highway driving, and using national average fuel prices. That estimate is a useful benchmark, but individual fuel costs will vary significantly based on specific driving habits, fuel prices in your area, and the type of fuel used. Remember that this car requires premium fuel, which usually adds a significant cost per gallon.

Real-world expectations

While the EPA figures provide a baseline, real-world fuel economy for the M850i Convertible will likely deviate, and often downwards. The intoxicating soundtrack and effortless acceleration encourage aggressive driving, which will undoubtedly diminish fuel efficiency. Consider that the official numbers are achieved under controlled testing conditions, whereas everyday driving involves a mix of factors like traffic congestion, weather conditions, and of course, driver behavior. Owners who regularly exploit the engine’s capabilities can expect to see numbers closer to the city rating, even on mixed driving cycles. Those who are more judicious with the throttle might approach the highway figure, but achieving it consistently will require considerable restraint. Be sure to check M850I MPG across all years.

How it compares

Compared to other high-performance convertibles, the M850i’s fuel economy is within a predictable range. A Porsche 911 Carrera S Cabriolet, while slightly less powerful, offers a comparable ownership experience but achieves around 20 MPG combined. The Mercedes-AMG SL 55, a direct competitor, lands in a similar ballpark. A less expensive Chevrolet Corvette Convertible manages slightly better fuel economy, around 19 MPG combined, courtesy of its clever cylinder deactivation technology. For buyers cross-shopping these vehicles, the slight differences in fuel economy may factor into the decision, but it’s unlikely to be a primary concern. Ultimately, the decision hinges on design, brand preference, and overall driving experience.

Tips to maximize efficiency

The most impactful way to improve fuel economy in your M850i Convertible is simple: moderate your throttle inputs. The car’s immense power is readily available, but resisting the urge to constantly accelerate hard will pay dividends at the pump. Smooth and gradual acceleration, especially from a standstill, can significantly reduce fuel consumption.

Use driving mode settings. The M850i offers various driving modes, including an “Eco Pro” mode that optimizes engine and transmission settings for efficiency. While it might temper the car’s responsiveness, activating this mode during highway cruising or in situations where performance is less critical can demonstrably improve your MPG.

Ensure your tires are properly inflated. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Regularly check your tire pressure and maintain the recommended levels specified in the owner’s manual. This simple maintenance task can have a surprising impact on fuel efficiency and tire life.

Reduce unnecessary weight. Carrying excess cargo in the trunk adds weight and negatively affects fuel economy. Remove any unnecessary items to lighten the load and improve your MPG. It seems trivial, but every little bit helps, especially when you consider the car is already quite hefty. Review all Bmw fuel economy data.