Choose the exact configuration
The 2021 BMW 8 Series records shown here span 2 drivetrain designation(s) and 1 fuel type(s). Match the record to your car before using a rating. Trim branding alone may not uniquely identify an EPA record.
| Configuration / source | Energy | Combined | Per month |
|---|---|---|---|
| 840i Convertible 3.0L 6-cyl · Automatic (S8) Rear-Wheel Drive EPA #42996 | Premium Gasoline | 25 MPG 22 city / 29 hwy | $160 $4.00/US gal |
| 840i Coupe 3.0L 6-cyl · Automatic (S8) Rear-Wheel Drive EPA #42920 | Premium Gasoline | 25 MPG 23 city / 30 hwy | $160 $4.00/US gal |
| 840i Gran Coupe 3.0L 6-cyl · Automatic (S8) Rear-Wheel Drive EPA #43002 | Premium Gasoline | 25 MPG 22 city / 29 hwy | $160 $4.00/US gal |
| 840i xDrive Convertible 3.0L 6-cyl · Automatic (S8) All-Wheel Drive EPA #42922 | Premium Gasoline | 23 MPG 20 city / 27 hwy | $174 $4.00/US gal |
| 840i xDrive Coupe 3.0L 6-cyl · Automatic (S8) All-Wheel Drive EPA #42921 | Premium Gasoline | 23 MPG 20 city / 27 hwy | $174 $4.00/US gal |
| 840i xDrive Gran Coupe 3.0L 6-cyl · Automatic (S8) All-Wheel Drive EPA #42938 | Premium Gasoline | 23 MPG 20 city / 27 hwy | $174 $4.00/US gal |
| M850i xDrive Coupe 4.4L 8-cyl · Automatic (S8) All-Wheel Drive EPA #43641 | Premium Gasoline | 20 MPG 17 city / 25 hwy | $200 $4.00/US gal |
Snapshot retrieved 2026-10-05. Rated MPG/MPGe is source data; dollar values are our calculations. Regular/diesel $3.50/gal; premium $4.00/gal; electricity $0.17/kWh. These are not current market averages.
How annual mileage changes the bill
For the lowest modeled energy-cost configuration here, 840i Convertible · Automatic (S8) · EPA #42996, the following scenarios use $4.00/US gal. This is not a recommendation to buy it.
| Annual miles | Monthly cost | Annual cost | Annual energy |
|---|---|---|---|
| 6,000 miles | $80 | $960 | 240.0 gal |
| 10,000 miles | $133 | $1,600 | 400.0 gal |
| 12,000 miles | $160 | $1,920 | 480.0 gal |
| 15,000 miles | $200 | $2,400 | 600.0 gal |
| 20,000 miles | $267 | $3,200 | 800.0 gal |
What changes the estimate?
At this configuration’s rating, every additional 1,000 miles adds approximately $160. Each extra $0.50 per gallon adds $240 a year at 12,000 miles. Your route, weather and speed can change consumption.
Understand the difference between EPA ratings and real-world use.
Compare this model with another car
Open the comparison with this configuration selected. Match model year, fuel and transmission for a useful comparison.
Is this the full cost of owning the car?
No. These figures cover energy only. They exclude purchase price, financing, depreciation, insurance, maintenance and tax.
Why might my specific trim be missing?
EPA configurations do not always match retail trim names. This edition excludes plug-in hybrids, dual-fuel vehicles and records without usable consumption values. Consult the linked official record and your window sticker.