2021 BMW M340i
The 2021 BMW M340i is a mild-hybrid sedan. It has a 3.0-litre turbocharged six-cylinder engine producing 382 hp (285 kW), with an 8-speed automatic and rear-wheel drive.
ABOUT THE 2021 BMW M340I
The 2021 BMW M340i is the performance flagship of the regular seventh-generation 3 Series (G20) saloon, sitting below the separate M3. It uses a 3.0-litre turbocharged inline-six rated at 382 hp and 369 lb-ft (500 Nm). This entry covers the rear-wheel-drive version with the eight-speed automatic; the M340i xDrive offered all-wheel drive.
Where 2021 sits
The G20 arrived for the 2019 model year and the M340i joined the range for 2020, so 2021 was only its second season. It predates the 2023 facelift, which means it has the earlier dashboard with separate instrument and central screens rather than the later curved display, plus more physical buttons for climate and audio.
What it is like
The M340i was designed as a quick, comfortable all-rounder rather than a track car. M Sport brakes and an electronically controlled M Sport rear differential were key parts of the package, and the engine pulls strongly from low revs. As a four-door saloon with a usable boot, it is easy to live with every day.
Buying one today
The B58 engine is generally regarded as robust. Known weak points are coolant leaks from plastic cooling-system parts and oil filter housing gasket seepage. Look for a full service history, and check tyres and brakes for signs of hard use.
Rivals
Competitors included the Audi S4, Mercedes-AMG C43, Genesis G70 3.3T and Kia Stinger GT.
Written by CarDetails.org. Last reviewed October 31, 2026.
SPECS
| Make | BMW | Model | M340i |
|---|---|---|---|
| Year | 2021 | Version / Trim | BMW 2021 M340i |
| Body Style | Sedan | Doors | 4 |
| Seats | 5 | Ext. Colour | Alpine White, Jet Black, Black Sapphire Metallic, Mineral White Metallic, Dravit Gray Metallic, Phytonic Blue Metallic, Portimao Blue Metallic, San Francisco Red Metallic, Carbon Black Metallic, Brooklyn Gray Metallic, Individual Colours available |
| Steering | LHD / RHD | Manufactured In | Germany |
| Drive | Rear-Wheel Drive (RWD) | Transmission | Automatic (S8) |
| Engine | 3.0L 6-cyl Turbo | Engine Size | 3,000 cc |
| Power | 382 hp / 285 kW | Torque | 500 Nm / 369 lb-ft |
| Range / Economy | 23 mpg city / 32 mpg hwy | ||
| Wheelbase | 2,851 mm | Kerb Weight | 1,730 kg (3,814 lb) |
HOW IT COMPARES WITH OTHER 2021 SEDANS
Compared with other 2021 sedans in our database, its 382 hp is 24% more than the average 2021 sedan (309 hp).
| 2021 BMW M340i | Average 2021 sedans | Difference | |
|---|---|---|---|
| Power | 382 hp | 309 hp (96 cars) | +24% |
| Torque | 500 Nm | 415 Nm (96 cars) | +20% |
| Kerb weight | 1,730 kg | 1,670 kg (104 cars) | +4% |
| Engine size | 3,000 cc | 2,615 cc (86 cars) | +15% |
Averages are calculated from all cars of the same model year and body type in the CarDetails.org database that have the figure listed. For 0–60 mph, a negative difference means quicker.
CLOSEST RIVALS
Other 2021 sedans with similar power to the 2021 BMW M340i.
| Car | Power | 0–60 mph | Kerb weight |
|---|---|---|---|
| 2021 BMW M340i | 382 hp | — | 1,730 kg |
| 2021 Tesla Model 3 Long Range AWD | 358 hp | 4.2 s | 1,752 kg |
| 2021 Audi S4 | 349 hp | 4.4 s | 1,750 kg |
| 2021 Toyota Avalon | 301 hp | 6.4 s | 1,680 kg |