Against 296 other Hybrid cars rated 2022–2024, the 340i trails their 28.1 mpg average by 2.1 mpg, about $110 a year. Averaged over the years each was sold, the most economical engine since 2016, the 3L 6-cyl Hybrid (2023–2024), does 26 mpg and the thirstiest, the 3L 6-cyl (2016–2019), 24.5: $90 a year apart.
Every BMW 340i engine, compared
Yearly cost assumes 12,000 miles at $3.20 a gallon.
| Engine | Combined | City / Highway | Years | Fuel per year |
|---|---|---|---|---|
| 3L 6-cyl Hybrid | 23 / 31 | 2023–2024 | $1,477 | |
| 3L 6-cyl | 21 / 31.3 | 2016–2019 | $1,567 |
What that actually costs
Against its rivals in the same model years, the Acura TLX gets 23 mpg, the Subaru WRX 22 mpg and the Genesis G70 22.8 mpg, next to 26 mpg for the 2024 340i. The 340i is the cheapest of them to run: $268 a year less than the Subaru WRX.
| Measure | Value |
|---|---|
| Cost per mile (2024) | $0.123 |
| Fuel per year | $1,477 |
| Fuel over five years | $7,385 |
| Against other Hybrid cars, 2022–2024 | +$110 a year |
| EPA's own estimate | $3,142 a year |
City or highway — who is this car for
The 2024 BMW 340i gives up 8 mpg in town: 31 on the highway against 23 in the city, $431 a year if every mile were city driving.
| Measure | Value | Reading |
|---|---|---|
| City (2024) | 23 mpg | $1,670 a year if you only drive in town |
| Highway | 31 mpg | $1,239 a year if you mostly commute |
| Gap | +8 mpg (35%) | Wide — this car dislikes traffic |
How the 340i changed over the years
The 340i peaked in 2024 at 26 mpg (23 city, 31 highway) and was at its thirstiest in 2019 at 23 — 3 mpg apart, or $193 a year in fuel between buying one year and the other.
| Model year | Combined | City / Highway | Engines offered | Fuel per year |
|---|---|---|---|---|
| 2024 | 23 / 31 | 1 | $1,477 | |
| 2023 | 23 / 31 | 1 | $1,477 | |
| 2019 | 20 / 29 | 1 | $1,670 | |
| 2018 | 21 / 32 | 1 | $1,536 | |
| 2017 | 21 / 32 | 1 | $1,536 | |
| 2016 | 22 / 32 | 1 | $1,536 |
MPG is a number. Dollars per year is the answer.
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How we count
This page rests on 6 EPA ratings of the BMW 340i — 2 engines across 2016–2024. 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 $3,142. Full method.
Frequently asked questions
What mpg does the 2024 BMW 340i get?
26 mpg combined, 23 city and 31 highway, per EPA. Across every year since 2016 the 340i has averaged 25 mpg.
Is the 2024 340i more efficient than the 2023?
About the same: 26 against 26 mpg combined.
Which 340i year has the best gas mileage?
The 2024, at 26 mpg combined (23 city, 31 highway), which is also the latest model year we hold.
Does the 340i get better gas mileage than the Acura TLX?
Yes: 26 mpg for the 2024 340i against 23 for the 2025 Acura TLX, about $193 a year less to run.
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