The BMW 3 Series M340i, specifically in its G20 LCI (Life Cycle Impulse – facelift) iteration produced from July 2022 to July 2024, represents a performance-oriented variant within the broader 3 Series sedan lineup. Positioned as a near-flagship trim, it bridges the gap between the more comfort-focused models and the fully-fledged M3. This version incorporates a mild hybrid system to enhance both performance and efficiency, building upon the established reputation of the 3 Series for a balanced driving experience. The LCI facelift brought updated styling, interior refinements, and revised technology compared to the initial G20 launch.
| Brand | BMW |
| Model | 3 Series |
| Generation | 3 Series Sedan (G20 LCI, facelift 2022) |
| Type (Engine) | M340i (382 Hp) Mild Hybrid Steptronic |
| Start of production | July, 2022 |
| End of production | July, 2024 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 10.2 l/100 km (23.1 US mpg) |
| Fuel consumption (extra urban) | 7.6 l/100 km (30.9 US mpg) |
| Fuel consumption (combined) | 9 l/100 km (26.1 US mpg) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 60 mph | 4.4 sec |
| Maximum speed | 210 km/h (130.49 mph) |
| Weight-to-power ratio | 4.6 kg/Hp |
| Weight-to-torque ratio | 3.5 kg/Nm |
| Gross battery capacity | 0.4 kWh |
| Battery voltage | 48 V |
| Battery technology | Lithium-ion (Li-Ion) |
| Electric motor power | 11 Hp |
| Electric motor Torque | 25 Nm (18.44 lb.-ft.) |
| Power | 382 Hp @ 5800-6500 rpm |
| Torque | 500 Nm @ 1800-5000 rpm (368.78 lb.-ft.) |
| Engine Model/Code | B58B30O1 |
| Engine displacement | 2998 cm3 (182.95 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 82 mm (3.23 in.) |
| Piston Stroke | 94.6 mm (3.72 in.) |
| Compression ratio | 10.2:1 |
| Engine oil capacity | 6.5 l (6.87 US qt) |
| Kerb Weight | 1739 kg (3833.84 lbs.) |
| Max. weight | 2200 kg (4850.17 lbs.) |
| Trunk (boot) space | 480 l (16.95 cu. ft.) |
| Fuel tank capacity | 59 l (15.59 US gal) |
| Length | 4723 mm (185.94 in.) |
| Width | 1827 mm (71.93 in.) |
| Height | 1433 mm (56.42 in.) |
| Wheelbase | 2851 mm (112.24 in.) |
| Number of gears | 8 |
| Gearbox type | Automatic (Steptronic) |
Powertrain & Engine Architecture
At the heart of the M340i LCI lies the B58B30O1 3.0-liter inline-six engine. This engine is a direct descendant of BMW’s long-standing tradition of smooth and powerful six-cylinder powerplants. The B58 features a single twin-scroll turbocharger, direct fuel injection, and BMW’s VALVETRONIC variable valve timing and Double-VANOS variable camshaft timing systems. These technologies work in concert to deliver a broad torque curve and responsive performance. The mild hybrid system, utilizing a 48V lithium-ion battery and an integrated starter generator, provides an additional 11 horsepower and 25 Nm (18.44 lb-ft) of torque, enabling smoother start-stop operation, and assisting during acceleration. The Steptronic 8-speed automatic transmission is standard, offering both fully automatic operation and manual shift control via steering wheel-mounted paddles. The transmission is tuned for both performance and efficiency, with quick and precise gear changes.
Driving Characteristics
The M340i LCI delivers a noticeably more engaging driving experience than the lower-trim 3 Series models. The 382 hp and 500 Nm (368.78 lb-ft) of torque provide strong acceleration, with a 0-60 mph time of just 4.4 seconds. The mild hybrid system contributes to a more seamless power delivery, minimizing turbo lag and providing an extra boost during overtaking maneuvers. The Steptronic transmission is well-matched to the engine, offering smooth shifts in automatic mode and responsive control in manual mode. While not as track-focused as the M3, the M340i offers a compelling balance of performance and everyday usability. The suspension is tuned to provide a comfortable ride without sacrificing handling precision.
Equipment & Trim Levels
The M340i LCI typically comes well-equipped as standard. Key features include sport seats, a premium audio system, BMW’s iDrive infotainment system with a large touchscreen display, and a comprehensive suite of driver-assistance systems. Interior upholstery is typically leatherette or leather, with aluminum or wood trim options available. Optional extras include a head-up display, adaptive cruise control, parking assist, and upgraded audio systems. The LCI facelift brought updated interior trim options and a revised dashboard layout. The M Sport package is a popular option, adding more aggressive styling cues, sport suspension, and larger brakes.
Chassis & Braking
The M340i LCI utilizes a sophisticated chassis design. The front suspension features spring struts with a transverse stabilizer, while the rear suspension employs an independent multi-link setup, also with a stabilizer bar. This configuration provides a good balance of ride comfort and handling precision. The braking system consists of ventilated discs at all four corners, providing ample stopping power. The M Sport brakes, available as an option, offer even greater stopping performance. The steering is electrically assisted, providing precise and responsive control.
Market Reception & Comparison
The M340i LCI has been widely praised by automotive critics for its performance, handling, and refinement. It is often seen as a sweet spot in the 3 Series lineup, offering a significant performance upgrade over the base models without the higher price tag and more hardcore focus of the M3. Fuel economy is respectable for a performance sedan, with combined figures around 26.1 US mpg. Compared to the 330i, the M340i offers a substantial power increase and a more engaging driving experience. Compared to the M3, the M340i is more comfortable and easier to live with on a daily basis, although it lacks the ultimate track performance of the M3.
Legacy
The B58 engine has proven to be a robust and reliable powerplant, and the M340i LCI is expected to hold its value well in the used car market. The mild hybrid system adds a layer of future-proofing, and the overall build quality of the G20 3 Series is generally considered to be excellent. While long-term reliability data is still emerging, early indications suggest that the M340i LCI is a well-engineered and durable vehicle. Its blend of performance, luxury, and technology makes it a desirable option for enthusiasts and everyday drivers alike.
