BMW 330i vs M340i
330i or M340i? Side-by-side specifications from the original factory data: engine, power, economy, dimensions and weight.
| Parameter | 330i | M340i |
|---|---|---|
| Engine | 4-cyl · 2.0L · turbo · Premium Gasoline | 6-cyl · 3.0L · turbo · Premium Gasoline |
| Displacement, cc | 2000 | 3000 |
| Cylinders | 4 | 6 |
| Power, hp | 255 | 382 |
| Transmission | Automatic (S8) | Automatic (S8) |
| Drivetrain | Rear-Wheel Drive | Rear-Wheel Drive |
| Parameter | 330i | M340i |
|---|---|---|
| MPG city | 26 | 23 |
| MPG highway | 36 | 32 |
| MPG combined | 30 | 26 |
| CO₂, g/mile | 298 | 333 |
| Parameter | 330i | M340i |
|---|---|---|
| Length, in | 185.4 | 185.4 |
| Width, in | 72.0 | 72.0 |
| Height, in | 56.7 | 56.7 |
| Wheelbase, in | 112.2 | 112.2 |
Figures based on official manufacturer materials. Actual values may vary by configuration and market.
What the table shows
The two columns are a 2021 330i and a 2021 M340i, taken from the specification cards behind this site rather than from a manufacturer’s press release. The starting version of a shared model year is used on both sides, so the comparison is base against base.
- Power: the M340i is more powerful by 127 hp — 382 against 255, 50% more.
- Combined economy: the 330i is more economical by 4 mpg — 30 against 26, 15% more.
Identical on length (185.4 in) — which is worth as much as the differences when deciding between them.
The 330i uses the B48, a 2.0-litre turbocharged four; the M340i the B58, a 3.0-litre turbocharged six. Both drive the rear wheels.
Rows the table leaves blank are figures neither card carries. Torque, acceleration and top speed are not collected by any US government source and appear on this site only where an original factory brochure printed them, so they are missing more often on recent cars than on older ones.