The BMW 3 Series Sedan (G20 LCI), specifically the M340d xDrive Steptronic variant, represents a significant evolution in the lineage of BMW’s iconic sports sedan. Introduced in July 2022 as part of the G20’s Life Cycle Impulse (LCI) facelift, this model combines a potent diesel engine with mild hybrid technology and all-wheel drive. It occupies a performance-oriented position within the 3 Series range, slotting below the full M3 but offering a compelling blend of power, efficiency, and luxury. The LCI updates brought revised styling, an updated interior, and enhanced technology, further solidifying the 3 Series’ reputation as a benchmark in the compact executive car segment.
Technical Specifications
| Brand | BMW |
| Model | 3 Series |
| Generation | 3 Series Sedan (G20 LCI, facelift 2022) |
| Type (Engine) | M340d (340 Hp) Mild Hybrid xDrive Steptronic |
| Start of production | July, 2022 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Combined fuel consumption (WLTP) | 5.9-6.4 l/100 km (39.9 – 36.8 US mpg, 47.9 – 44.1 UK mpg, 16.9 – 15.6 km/l) |
| CO2 emissions (WLTP) | 154-168 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 4.6 sec |
| Acceleration 0 – 62 mph | 4.6 sec |
| Acceleration 0 – 60 mph | 4.4 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6d |
| Weight-to-power ratio | 5.3 kg/Hp, 188.9 Hp/tonne |
| Weight-to-torque ratio | 2.6 kg/Nm, 388.9 Nm/tonne |
| Gross battery capacity | 0.4 kWh |
| Battery voltage | 48 V |
| Battery technology | Lithium-ion (Li-Ion) |
| Battery location | Under the front hood |
| Electric motor power | 11 Hp |
| Electric motor Torque | 25 Nm (18.44 lb.-ft.) |
| Electric motor location | Front, Longitudinal |
| Power | 340 Hp @ 4400 rpm |
| Torque | 700 Nm @ 1750-2250 rpm (516.29 lb.-ft. @ 1750-2250 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | B57D30B |
| Engine displacement | 2993 cm3 (182.64 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 84 mm (3.31 in.) |
| Piston Stroke | 90 mm (3.54 in.) |
| Compression ratio | 16.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Twin-power turbo, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 7 l (7.4 US qt | 6.16 UK qt) |
| Kerb Weight | 1800 kg (3968.32 lbs.) |
| Max. weight | 2340 kg (5158.82 lbs.) |
| Max load | 540 kg (1190.5 lbs.) |
| Trunk (boot) space – minimum | 480 l (16.95 cu. ft.) |
| Fuel tank capacity | 59 l (15.59 US gal | 12.98 UK gal) |
| Max. roof load | 75 kg (165.35 lbs.) |
| Permitted trailer load with brakes (12%) | 1800 kg (3968.32 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 75 kg (165.35 lbs.) |
| Length | 4713 mm (185.55 in.) |
| Width | 1827 mm (71.93 in.) |
| Width including mirrors | 2068 mm (81.42 in.) |
| Height | 1445 mm (56.89 in.) |
| Wheelbase | 2851 mm (112.24 in.) |
| Front track | 1583 mm (62.32 in.) |
| Rear (Back) track | 1567 mm (61.69 in.) |
| Front overhang | 803 mm (31.61 in.) |
| Rear overhang | 1059 mm (41.69 in.) |
| Ride height (ground clearance) | 135 mm (5.31 in.) |
| Drag coefficient (Cd) | 0.27 |
| Minimum turning circle (turning diameter) | 12 m (39.37 ft.) |
| Drivetrain Architecture | ICE and electric motor drive all four wheels, operating in mixed mode. |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 8 gears, automatic transmission Steptronic |
| Front suspension | Spring Strut, Transverse stabilizer |
| Rear suspension | Independent multi-link spring suspension with stabilizer |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | Front: 225/45 R18, Rear: 255/40 R18 |
| Wheel rims size | Front: 7.5J x 18, Rear: 8.5J x 18 |
Powertrain & Engine Architecture
The heart of the M340d xDrive is BMW’s B57D30B 3.0-liter inline-six diesel engine. This engine benefits from a comprehensive overhaul compared to its predecessors, incorporating a multi-stage turbocharging system – a low-inertia turbocharger for immediate response and a larger turbocharger for peak power. The engine utilizes a sophisticated common-rail direct injection system operating at extremely high pressures (2,500 bar) to optimize combustion efficiency and reduce emissions. The mild hybrid system, utilizing a 48V electrical architecture, adds a 11 hp electric motor integrated into the drivetrain. This system provides a power boost during acceleration, enables smoother start-stop operation, and allows for coasting with the engine switched off, further enhancing fuel economy. The engine is paired with BMW’s eight-speed Steptronic automatic transmission, known for its quick and smooth shifts. This transmission is specifically tuned for the M340d, with optimized shift points to maximize performance and efficiency.
Driving Characteristics
The M340d xDrive delivers a compelling driving experience. The 700 Nm (516 lb-ft) of torque available from 1750-2250 rpm provides effortless acceleration in any gear. The mild hybrid system effectively mitigates turbo lag, resulting in a responsive and linear power delivery. While not as overtly sporty as the M3, the M340d offers a refined and engaging driving experience, particularly on winding roads. The xDrive all-wheel-drive system provides excellent traction and stability, inspiring confidence in various weather conditions. Compared to the 320d or 330i variants, the M340d offers significantly more performance, but at the expense of some fuel economy. The automatic transmission is well-matched to the engine, providing smooth and timely shifts, although some drivers may prefer the greater control offered by a manual gearbox (which is not available in this configuration).
Equipment & Trim Levels
The M340d xDrive typically comes well-equipped as standard. Key features include BMW’s Live Cockpit Professional (digital instrument cluster and infotainment system), leather upholstery, sport seats, and a premium sound system. Exterior styling cues include M Sport aerodynamic enhancements, shadowline trim, and larger alloy wheels. Optional extras include adaptive suspension, a head-up display, panoramic sunroof, and various driver-assistance systems such as adaptive cruise control and lane-keeping assist. The interior trim options range from aluminum to wood veneers, allowing for a degree of personalization.
Chassis & Braking
The M340d xDrive features a chassis tuned for a balance of comfort and handling. The front suspension utilizes a spring strut design with a transverse stabilizer, while the rear employs an independent multi-link setup, also with a stabilizer bar. The suspension is slightly stiffer than that of lower-powered 3 Series models to provide better body control. Braking is handled by ventilated discs on all four wheels, providing ample stopping power. The ABS system is complemented by electronic brakeforce distribution and brake assist.
Market Reception & Comparison
The M340d xDrive has been generally well-received by automotive critics. It’s praised for its strong performance, refined ride, and efficient engine. Compared to its main rivals, such as the Audi S4 and Mercedes-AMG C 300 d, the M340d often stands out for its engaging driving dynamics and sophisticated technology. Fuel economy is a strong point, with real-world figures typically falling within the 5.9-6.4 l/100 km range. Reliability has been generally good, although some owners have reported minor issues with the infotainment system.
Legacy
The B57 engine family, including the B57D30B found in the M340d, has proven to be a robust and reliable powerplant. The mild hybrid technology introduced in this model represents a step towards greater electrification in BMW’s lineup. On the used car market, the M340d xDrive (G20 LCI) holds its value well due to its performance, features, and reputation for reliability. It remains a desirable option for buyers seeking a sporty and efficient executive sedan.
