Against 247 other V6 cars rated 2024–2026, the 840i beats their 21 mpg average by 3 mpg, about $229 a year.
Every BMW 840i engine, compared
The BMW 840i was rated in a single specification, so its gas mileage does not vary by version — only by model year. Yearly cost assumes 12,000 miles at $3.20 a gallon.
| Engine | Combined | City / Highway | Years | Fuel per year |
|---|---|---|---|---|
| 3L 6-cyl | 21.6 / 29.1 | 2020–2026 | $1,574 |
What that actually costs
Against its rivals in the same model years, the Bentley Continental gets 19 mpg, the Lexus LC 21.7 mpg and the Audi RS 5 20 mpg, next to 24 mpg for the 2026 840i. The 840i is the cheapest of them to run: $421 a year less than the Bentley Continental.
| Measure | Value |
|---|---|
| Cost per mile (2026) | $0.133 |
| Fuel per year | $1,600 |
| Fuel over five years | $8,000 |
| Against other V6 cars, 2024–2026 | −$229 a year |
| EPA's own estimate | $3,157 a year |
City or highway — who is this car for
The 2026 BMW 840i gives up 8 mpg in town: 29 on the highway against 21 in the city, $505 a year if every mile were city driving.
| Measure | Value | Reading |
|---|---|---|
| City (2026) | 21 mpg | $1,829 a year if you only drive in town |
| Highway | 29 mpg | $1,324 a year if you mostly commute |
| Gap | +8 mpg (38%) | Wide — this car dislikes traffic |
How the 840i changed over the years
The 840i peaked in 2022 at 25 mpg (22 city, 29 highway) and was at its thirstiest in 2026 at 24 — 1 mpg apart, or $64 a year in fuel between buying one year and the other. The 2026 car does 24.
| Model year | Combined | City / Highway | Engines offered | Fuel per year |
|---|---|---|---|---|
| 2026 | 21 / 29 | 1 | $1,600 | |
| 2025 | 21 / 29 | 1 | $1,600 | |
| 2024 | 21 / 29 | 1 | $1,600 | |
| 2023 | 21 / 29 | 1 | $1,600 | |
| 2022 | 22 / 29 | 1 | $1,536 | |
| 2021 | 22 / 29 | 1 | $1,536 | |
| 2020 | 23 / 30 | 1 | $1,536 |
MPG is a number. Dollars per year is the answer.
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How we count
This page rests on 7 EPA ratings of the BMW 840i — 1 engine across 2020–2026. The mileage is EPA's laboratory figure, unchanged; the yearly bill is ours, at 12,000 miles and $3.20 a gallon, against EPA's own estimate of $3,157. Full method.
Frequently asked questions
What mpg does the 2026 BMW 840i get?
24 mpg combined, 21 city and 29 highway, per EPA. Across every year since 2020 the 840i has averaged 24.4 mpg.
Is the 2026 840i more efficient than the 2025?
About the same: 24 against 24 mpg combined.
Which 840i year has the best gas mileage?
The 2022, at 25 mpg combined (22 city, 29 highway).
Does the 840i get better gas mileage than the Bentley Continental?
Yes: 24 mpg for the 2026 840i against 19 for the 2026 Bentley Continental, about $421 a year less to run.
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