The BMW 3 Series Touring (G21) M340i xDrive Steptronic, produced from 2019 to 2022, represents a high-performance variant within the sixth generation (G21) of BMW’s popular 3 Series Touring – the wagon (estate) version of the 3 Series. Positioned as a premium offering, the M340i combined practical estate car versatility with the performance characteristics traditionally associated with BMW’s M-branded vehicles. It served as a compelling alternative to traditional sports sedans, offering increased cargo capacity without sacrificing driving dynamics. This model was primarily marketed in Europe and North America, catering to buyers seeking a blend of luxury, performance, and practicality.
Technical Specifications
| Brand | BMW |
| Model | 3 Series |
| Generation | 3 Series Touring (G21) |
| Type | M340i (374 Hp) xDrive Steptronic |
| Start of production | 2019 |
| End of production | 2022 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Station wagon (estate) |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption (urban) | 9.2-9.7 l/100 km (25.6 – 24.2 US mpg) |
| Fuel consumption (extra urban) | 5.9-6.3 l/100 km (39.9 – 37.3 US mpg) |
| Fuel consumption (combined) | 7.2-7.6 l/100 km (32.7 – 30.9 US mpg) |
| CO2 emissions | 163-172 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 4.5 sec |
| Acceleration 0 – 62 mph | 4.5 sec |
| Acceleration 0 – 60 mph | 4.3 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6d – TEMP |
| Weight-to-power ratio | 4.7 kg/Hp |
| Weight-to-torque ratio | 3.5 kg/Nm |
| Power | 374 Hp @ 5500-6500 rpm |
| Torque | 500 Nm @ 1850-5000 rpm (368.78 lb.-ft. @ 1850-5000 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | B58B30B |
| 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 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Twin-power turbo, Intercooler |
| Engine oil capacity | 6.5 l (6.87 US qt | 5.72 UK qt) |
| Coolant | 10.5 l (11.1 US qt | 9.24 UK qt) |
| Kerb Weight | 1770 kg (3902.18 lbs.) |
| Max. weight | 2365 kg (5213.93 lbs.) |
| Max load | 595 kg (1311.75 lbs.) |
| Trunk (boot) space – minimum | 500 l (17.66 cu. ft.) |
| Trunk (boot) space – maximum | 1510 l (53.33 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.) |
| Height | 1440 mm (56.69 in.) |
| Wheelbase | 2851 mm (112.24 in.) |
| Front track | 1583 mm (62.32 in.) |
| Rear track | 1567 mm (61.69 in.) |
| Ride height (ground clearance) | 130 mm (5.12 in.) |
| Drag coefficient (Cd) | 0.29 |
| Minimum turning circle | 12.0 m (39.37 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears | 8 |
| Gearbox type | automatic transmission Steptronic |
| Front suspension | Independent coil spring |
| Rear suspension | Independent multi-link suspension |
| 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 |
| Front tires | 225/45 R18 95Y XL |
| Rear tires | 255/40 R18 99Y XL |
| Front wheel rims | 7.5J x 18 |
| Rear wheel rims | 8.5J x 18 |
Powertrain & Engine Architecture
The M340i xDrive Steptronic is powered by the BMW B58B30B, a 3.0-liter inline-six cylinder engine. This engine is a member of BMW’s modular engine family, known for its smooth power delivery and efficiency. The B58 utilizes direct fuel injection, a twin-scroll turbocharger, and variable valve timing (VANOS) and valve lift (Valvetronic) technologies to optimize performance and fuel economy. The engine produces 374 horsepower at 5,500-6,500 rpm and 368.78 lb-ft of torque between 1,850 and 5,000 rpm. The engine is longitudinally mounted, driving all four wheels through BMW’s xDrive all-wheel-drive system. The transmission is an 8-speed Steptronic automatic, offering smooth and quick shifts. This transmission features a torque converter and allows for both automatic and manual gear selection via steering wheel-mounted paddles.
Driving Characteristics
The M340i Touring delivers a compelling driving experience. The combination of the potent inline-six engine and the xDrive all-wheel-drive system results in rapid acceleration – 0 to 60 mph in approximately 4.3 seconds. The Steptronic transmission is well-tuned, providing seamless gear changes in automatic mode and responsive control when using the manual shift function. Compared to lower-powered 3 Series Touring variants (like the 320i or 330i), the M340i offers significantly more power and torque, resulting in a more engaging and confident driving experience. While the added weight of the all-wheel-drive system and wagon body style slightly impacts agility compared to the 3 Series sedan, the M340i still handles remarkably well, offering precise steering and a well-controlled ride. The gear ratios are optimized for both acceleration and highway cruising, providing ample power for overtaking maneuvers.
Equipment & Trim Levels
The M340i xDrive Steptronic came generously equipped as standard. Key features included BMW’s Live Cockpit Professional (a fully digital instrument cluster and infotainment system), leather upholstery, power-adjustable front seats with memory function, automatic climate control, and a premium sound system. Exterior features included M-specific styling cues such as an aggressive front bumper, side skirts, and a rear diffuser. Optional extras included a panoramic sunroof, adaptive suspension, upgraded leather options, and various driver-assistance systems like adaptive cruise control and lane-keeping assist. The interior dashboard configuration was typical of the G21 3 Series, with a driver-focused layout and high-quality materials.
Chassis & Braking
The M340i Touring features a sophisticated chassis designed to handle the increased power output. The front suspension utilizes independent coil springs, while the rear employs an independent multi-link setup. The suspension is tuned to provide a balance between comfort and sporty handling. Braking duties are handled by ventilated discs on all four wheels, providing ample stopping power. The M340i also incorporates BMW’s Dynamic Stability Control (DSC) system, which helps to maintain stability during cornering and emergency maneuvers. A slightly thicker stabilizer bar was used compared to lower-trim models to reduce body roll.
Market Reception & Comparison
The M340i Touring was generally well-received by automotive critics. It was praised for its powerful engine, engaging driving dynamics, and practical wagon body style. Compared to other trims in the 3 Series Touring lineup, the M340i offered a significant performance upgrade, but at a higher price point. Fuel economy was respectable for a performance vehicle, averaging around 32.7 mpg combined. Reliability reports have been generally positive, with the B58 engine proving to be a robust and dependable unit. However, like any complex modern vehicle, the M340i is not immune to potential issues with its electronic systems or turbocharger.
Legacy
The BMW M340i xDrive Steptronic (G21) has established itself as a desirable used car. The B58 engine is highly regarded by enthusiasts for its performance and tunability. The combination of performance, practicality, and relative reliability has ensured strong demand in the used car market. While maintenance costs can be higher than those of lower-powered 3 Series variants, the M340i offers a unique blend of attributes that continue to appeal to buyers seeking a premium performance wagon.
