The BMW X4 M40d xDrive Steptronic, produced from 2018 to August 2020, represents a performance-oriented variant within the second generation (G02) of the X4 Sports Activity Coupe. Positioned as a mid-to-high range offering, it bridged the gap between the more accessible four-cylinder models and the full-fledged X4 M. This model aimed to deliver a blend of luxury, practicality, and engaging driving dynamics, appealing to buyers seeking a sporty SUV with robust diesel power. It was primarily marketed in Europe and other regions where diesel engines remained popular, offering a compelling alternative to gasoline-powered competitors.
Technical Specifications
| Brand | BMW |
| Model | X4 |
| Generation | X4 (G02) |
| Type (Engine) | M40d (326 Hp) xDrive Steptronic |
| Start of production | 2018 |
| End of production | August, 2020 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | SAC (Sports Activity Coupe) |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption (urban) | 7.2-7.3 l/100 km (32.7 – 32.2 US mpg) |
| Fuel consumption (extra urban) | 5.9-6.3 l/100 km (39.9 – 37.3 US mpg) |
| Fuel consumption (combined) | 6.4-6.6 l/100 km (36.8 – 35.6 US mpg) |
| CO2 emissions | 170-173 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 4.9 sec |
| Acceleration 0 – 62 mph | 4.9 sec |
| Acceleration 0 – 60 mph | 4.7 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 5.8 kg/Hp, 172 Hp/tonne |
| Weight-to-torque ratio | 2.8 kg/Nm, 358.8 Nm/tonne |
| Power | 326 Hp @ 4400 rpm |
| Power per litre | 108.9 Hp/l |
| Torque | 680 Nm @ 1750-2750 rpm (501.54 lb.-ft. @ 1750-2750 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 |
| Engine oil capacity | 6.5 l (6.87 US qt | 5.72 UK qt) |
| Coolant | 10.2 l (10.78 US qt | 8.97 UK qt) |
| Kerb Weight | 1895 kg (4177.76 lbs.) |
| Max. weight | 2525 kg (5566.67 lbs.) |
| Max load | 630 kg (1388.91 lbs.) |
| Trunk (boot) space – minimum | 525 l (18.54 cu. ft.) |
| Trunk (boot) space – maximum | 1430 l (50.5 cu. ft.) |
| Fuel tank capacity | 68 l (17.96 US gal | 14.96 UK gal) |
| Max. roof load | 100 kg (220.46 lbs.) |
| Permitted trailer load with brakes (12%) | 2000 kg (4409.25 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 100 kg (220.46 lbs.) |
| Length | 4752 mm (187.09 in.) |
| Width | 1938 mm (76.3 in.) |
| Height | 1621 mm (63.82 in.) |
| Wheelbase | 2864 mm (112.76 in.) |
| Front track | 1615 mm (63.58 in.) |
| Rear (Back) track | 1624 mm (63.94 in.) |
| Ride height (ground clearance) | 204 mm (8.03 in.) |
| Drag coefficient (Cd) | 0.32 |
| Minimum turning circle (turning diameter) | 12.1 m (39.7 ft.) |
| Wading depth | 500 mm (19.69 in.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 8 gears, automatic transmission Steptronic |
| Front suspension | Double wishbone |
| 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 |
| Tires size | 245/45 R20; 275/40 R20 |
| Wheel rims size | 8J x 20; 9.5J x 20 |
Powertrain & Engine Architecture
The heart of the X4 M40d is BMW’s B57D30B inline-six cylinder diesel engine. This engine is a member of the modular BMW engine family, known for its robust construction and sophisticated technology. The B57 utilizes a common-rail direct injection system, delivering fuel at extremely high pressures for optimized combustion. A key feature is its twin-scroll turbocharger, which minimizes turbo lag and provides a broad torque curve. The engine also incorporates variable valve timing (Valvetronic) and Double VANOS (variable camshaft timing) for both intake and exhaust valves, further enhancing efficiency and responsiveness. The 8-speed Steptronic automatic transmission is integral to the M40d’s performance. This transmission features a torque converter and allows for both fully automatic operation and manual gear selection via steering wheel-mounted paddles. The transmission is programmed for smooth shifts and quick responses, complementing the engine’s characteristics.
Driving Characteristics
The X4 M40d delivers a distinctly sporty driving experience for a diesel-powered SUV. The 680 Nm (501.54 lb-ft) of torque, available from a low 1750 rpm, provides strong acceleration in virtually any gear. The 0-60 mph time of around 4.7 seconds is impressive for a vehicle of this size and weight. The xDrive all-wheel-drive system ensures excellent traction, particularly in adverse weather conditions. Compared to the base X4 models with four-cylinder engines, the M40d offers a significantly more powerful and refined driving experience. While not as overtly aggressive as the X4 M, it provides a compelling balance between performance and everyday usability. The automatic transmission is well-tuned, offering smooth gear changes during normal driving and quick downshifts when more power is needed.
Equipment & Trim Levels
The M40d trim typically included a generous array of standard features. Interior appointments included sport seats upholstered in premium leather, often with contrasting stitching. Standard equipment often included BMW’s iDrive infotainment system with a large central display, navigation, and Apple CarPlay compatibility. Other common features were automatic climate control, a panoramic sunroof, and a premium sound system. Optional extras included adaptive suspension, upgraded leather upholstery, and various driver-assistance systems such as lane departure warning and adaptive cruise control. The exterior styling of the M40d was also distinguished by unique design elements, such as M-specific aerodynamic enhancements, larger exhaust outlets, and distinctive alloy wheels.
Chassis & Braking
The X4 M40d features a robust chassis designed to handle the engine’s power and provide a comfortable ride. The front suspension utilizes a double-wishbone design, while the rear employs an independent multi-link setup. This configuration provides excellent wheel control and minimizes body roll during cornering. The M40d is equipped with ventilated disc brakes on all four wheels, providing ample stopping power. The braking system is also integrated with ABS (Anti-lock Braking System) and other electronic stability control systems. Compared to lower-spec X4 models, the M40d often featured stiffer springs and dampers, contributing to a more controlled and engaging driving experience.
Market Reception & Comparison
The X4 M40d was generally well-received by automotive critics. It was praised for its powerful engine, refined ride, and sporty handling. Reviewers noted that it offered a compelling alternative to gasoline-powered performance SUVs, particularly for buyers who prioritize fuel economy. Compared to the X4 30d (a less powerful diesel variant), the M40d offered a significant performance upgrade, albeit at a higher price point. Fuel economy figures of around 36.8 – 35.6 US mpg (combined) were considered respectable for a vehicle of this size and performance. Reliability reports have generally been positive, with the B57 engine proving to be a durable and dependable unit.
Legacy
The BMW X4 M40d (G02) has established itself as a desirable used car option. The B57 engine is known for its longevity and relatively low maintenance costs, making it an attractive choice for buyers seeking a reliable performance SUV. While newer X4 models have been introduced, the G02 M40d continues to hold its value well, reflecting its strong performance, luxurious features, and overall build quality. The combination of diesel efficiency and sporty driving dynamics continues to appeal to a niche market, ensuring its continued presence on the used car market for years to come.
