The BMW 4 Series Gran Coupe (G26 LCI), specifically the 420d variant with 190 horsepower, represents a mid-cycle refresh of the G26 generation introduced in July 2024. This model blends the sporty aesthetics of the 4 Series coupe with the practicality of a five-door Gran Coupe body style. Positioned as a mainstream offering within the 4 Series lineup, the 420d xDrive Steptronic caters to buyers seeking a balance of performance, efficiency, and all-weather capability. It slots below the more powerful 430i and M440i models, offering a more accessible entry point into the 4 Series Gran Coupe range.
Technical Specifications
| Brand | BMW |
| Model | 4 Series |
| Generation | 4 Series Gran Coupe (G26 LCI, facelift 2024) |
| Type (Engine) | 420d (190 Hp) Mild Hybrid xDrive Steptronic |
| Start of production | July, 2024 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Coupe |
| Seats | 5 |
| Doors | 5 |
| Combined fuel consumption (WLTP) | 5.3-6 l/100 km (44.4 – 39.2 US mpg, 53.3 – 47.1 UK mpg, 18.9 – 16.7 km/l) |
| CO2 emissions (WLTP) | 139-156 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 7.6 sec |
| Acceleration 0 – 62 mph | 7.6 sec |
| Acceleration 0 – 60 mph | 7.2 sec |
| Maximum speed | 233 km/h (144.78 mph) |
| Emission standard | Euro 6e |
| Weight-to-power ratio | 9.3 kg/Hp, 108 Hp/tonne |
| Weight-to-torque ratio | 4.4 kg/Nm, 227.3 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 | 190 Hp @ 4000 rpm |
| Torque | 400 Nm @ 1750-2500 rpm (295.02 lb.-ft. @ 1750-2500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | B47D20B |
| Engine displacement | 1995 cm3 (121.74 cu. in.) |
| Number of cylinders | 4 |
| 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 | 5.5 l (5.81 US qt | 4.84 UK qt) |
| Kerb Weight | 1760 kg (3880.14 lbs.) |
| Max. weight | 2315 kg (5103.7 lbs.) |
| Max load | 555 kg (1223.57 lbs.) |
| Trunk (boot) space – minimum | 470 l (16.6 cu. ft.) |
| Trunk (boot) space – maximum | 1290 l (45.56 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%) | 1600 kg (3527.4 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 75 kg (165.35 lbs.) |
| Length | 4783 mm (188.31 in.) |
| Width | 1852 mm (72.91 in.) |
| Width including mirrors | 2073 mm (81.61 in.) |
| Height | 1442 mm (56.77 in.) |
| Wheelbase | 2856 mm (112.44 in.) |
| Front track | 1597 mm (62.87 in.) |
| Rear (Back) track | 1624 mm (63.94 in.) |
| Front overhang | 862 mm (33.94 in.) |
| Rear overhang | 1065 mm (41.93 in.) |
| Ride height (ground clearance) | 140 mm (5.51 in.) |
| Drag coefficient (Cd) | 0.26 |
| 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 | 225/55 R17 |
| Wheel rims size | 7.5J x 17 |
Powertrain & Engine Architecture
The 420d Gran Coupe LCI is powered by the BMW B47D20B, a 2.0-liter inline-four cylinder diesel engine. This engine benefits from BMW’s latest diesel technology, including a high-pressure common rail direct injection system and a twin-scroll turbocharger. The addition of a 48V mild hybrid system provides a small power boost (11 hp) and enables features like smoother start-stop operation and extended coasting. The engine produces 190 horsepower at 4,000 rpm and 400 Nm (295 lb-ft) of torque between 1,750 and 2,500 rpm. This torque output is a key characteristic of modern diesel engines, providing strong low-end and mid-range acceleration. The engine is paired with an 8-speed Steptronic automatic transmission, known for its smooth and quick shifts. This transmission is crucial for optimizing fuel efficiency and delivering a comfortable driving experience.
Driving Characteristics
The 420d xDrive Steptronic offers a refined and comfortable driving experience. While not as overtly sporty as the higher-powered 4 Series variants, the 190 hp engine and all-wheel-drive system provide ample performance for everyday driving and highway cruising. The 8-speed automatic transmission is well-tuned, offering seamless gear changes and contributing to the car’s overall smoothness. The mild hybrid system enhances efficiency, particularly in urban environments. Compared to a manual transmission version (if offered), the automatic prioritizes ease of use and fuel economy over outright driver engagement. The xDrive all-wheel-drive system provides enhanced traction and stability, especially in inclement weather conditions.
Equipment & Trim Levels
The 420d Gran Coupe LCI typically comes standard with a comprehensive suite of features, including BMW’s iDrive infotainment system with a touchscreen display, automatic climate control, leatherette upholstery, and a range of driver-assistance systems such as lane departure warning and forward collision warning. Optional extras include premium leather upholstery, a head-up display, a panoramic sunroof, and a Harman Kardon sound system. Trim levels may vary depending on the market, but generally offer increasing levels of luxury and technology.
Chassis & Braking
The 4 Series Gran Coupe utilizes a sophisticated chassis design featuring a MacPherson strut front suspension and a multi-link rear suspension. The suspension is tuned to provide a balance between comfort and handling. The xDrive all-wheel-drive system distributes power between the front and rear axles as needed, optimizing traction and stability. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power. The car is equipped with ABS, electronic stability control, and other advanced braking systems.
Market Reception & Comparison
The 420d xDrive Steptronic has been generally well-received by automotive critics. It is praised for its fuel efficiency, comfortable ride, and refined driving experience. Compared to the more powerful 430i and M440i models, the 420d offers a more affordable entry point into the 4 Series Gran Coupe range. It also provides better fuel economy than its gasoline-powered counterparts. However, some critics note that the 420d lacks the outright performance of the higher-powered models. Compared to other diesel-powered Gran Coupes in its class, the 420d offers a compelling combination of performance, efficiency, and luxury.
Legacy
The B47 engine family, including the B47D20B, has proven to be relatively reliable, although some early versions experienced issues with timing chain wear. The 48V mild hybrid system is a relatively new technology, and its long-term reliability is still being assessed. As a used car, the 420d Gran Coupe LCI is expected to hold its value well, thanks to BMW’s strong brand reputation and the car’s appealing combination of practicality, performance, and efficiency. Regular maintenance, including oil changes and adherence to BMW’s recommended service intervals, is crucial for ensuring the long-term reliability of this powertrain.
