BMW M850i xDrive Convertible
19 MPG The 2026 BMW M850i xDrive Convertible is EPA-rated at 19 MPG combined (17 city / 24 highway). Over 15,000 miles a year that is about 789 gallons, $2526 a year in fuel, or $0.168 per mile at $3.20/gal.
Across its full 2019–2026 run it averages 19.3 MPG, falling by 1 MPG over 8 model years.
Running cost at different fuel prices and mileages
The figure everyone actually wants, and the one the EPA does not publish — because it depends on a fuel price no agency will commit to.
| Fuel price | Per mile | 10,000 mi/yr | 15,000 mi/yr | 20,000 mi/yr |
|---|---|---|---|---|
| $2.50/gal | $0.132 | $1316 | $1974 | $2632 |
| $3.00/gal | $0.158 | $1579 | $2368 | $3158 |
| $3.20/gal | $0.168 | $1684 | $2526 | $3368 |
| $3.50/gal | $0.184 | $1842 | $2763 | $3684 |
| $4.00/gal | $0.211 | $2105 | $3158 | $4211 |
| $4.50/gal | $0.237 | $2368 | $3553 | $4737 |
| $5.00/gal | $0.263 | $2632 | $3947 | $5263 |
Every model year
| Year | Combined | City | Highway | EPA fuel cost/yr | CO₂ g/mi | Trims |
|---|---|---|---|---|---|---|
| 2026 | 19 MPG | 17 | 24 | $4050 | 456 | 1 |
| 2025 | 19 MPG | 17 | 24 | $4050 | 458 | 1 |
| 2024 | 19 MPG | 17 | 24 | $4050 | 457 | 1 |
| 2023 | 19 MPG | 17 | 24 | $4050 | 457 | 1 |
| 2022 | 19 MPG | 17 | 24 | $4050 | 454 | 1 |
| 2021 | 19 MPG | 17 | 24 | $4050 | 453 | 1 |
| 2020 | 20 MPG | 17 | 25 | $3850 | 450 | 1 |
| 2019 | 20 MPG | 17 | 26 | $3850 | 434 | 1 |
Where a model year offered several engines or drivetrains, the figure is the average across all EPA-tested trims that year — the trim count is shown so you can see how much averaging is involved.
How it compares in its class
Among the 229 subcompact cars models tracked here, the BMW M850i xDrive Convertible ranks 173 on current figures, against a class average of 24.2 MPG.
Closest more-efficient alternatives in the same class: BMW M4 Convertible (19.5), Infiniti G37 Convertible (19.5), Pontiac Firebird/Formula (19.5), Saab 900 Convertible (19.8), Audi RS 5 (20).
Tailpipe CO₂ is rated at 456 grams per mile, which works out to roughly 6.8 tonnes a year at 15,000 miles.
Questions
What MPG does the BMW M850i xDrive Convertible get?
The 2026 BMW M850i xDrive Convertible is rated at 19 MPG combined by the EPA — 17 city and 24 highway. Across all 8 model years in the database it averages 19.3 MPG, ranging from 19 to 20 depending on year and trim.
How much does a BMW M850i xDrive Convertible cost in fuel per year?
At 19 MPG and 15,000 miles a year, it burns about 789 gallons — roughly $2526 a year with fuel at $3.20 a gallon, or $0.168 per mile. The EPA's own published annual figure for the 2026 model is $4050.
Has the BMW M850i xDrive Convertible become more efficient over time?
No — it has actually gone backwards, from 20 MPG in 2019 to 19 in 2026. That usually reflects the model growing heavier, more powerful, or moving upmarket rather than the engineering getting worse.
Is the BMW M850i xDrive Convertible efficient for its class?
It ranks 173 of 229 in the Subcompact Cars class on current figures, against a class average of 24.2 MPG. That is 5.2 worse than typical for the class.
EPA test figures from fueleconomy.gov. Cost per mile and annual fuel spend are computed at a reference price of $3.20 per gallon — use your own price. Estimates based on official test figures and average fuel prices. Real-world consumption varies with driving style, load, terrain and maintenance.