The BMW 4 Series Gran Coupe (F36), specifically the 420i xDrive Steptronic model produced from 2017 to 2021, represents a compelling blend of practicality and BMW’s signature driving dynamics. Positioned as a mid-range offering within the 4 Series Gran Coupe lineup, this variant aimed to provide a balance between performance and efficiency, appealing to buyers seeking a stylish and versatile vehicle. The facelifted F36, introduced in 2017, brought updated styling cues, improved technology, and refinements to the powertrain. This model occupied a space between the base 420i and the more powerful 430i and 440i variants, offering all-wheel drive as standard and an automatic transmission for ease of use.
Technical Specifications
| Brand | BMW |
| Model | 4 Series |
| Generation | 4 Series Gran Coupe (F36, facelift 2017) |
| Type (Engine) | 420i (184 Hp) xDrive Steptronic |
| Start of production | 2017 |
| End of production | 2021 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 7.7-8.1 l/100 km (30.5 – 29 US mpg, 36.7 – 34.9 UK mpg, 13 – 12.3 km/l) |
| Fuel consumption (extra urban) | 4.8-5.1 l/100 km (49 – 46.1 US mpg, 58.9 – 55.4 UK mpg, 20.8 – 19.6 km/l) |
| Fuel consumption (combined) | 5.9-6.2 l/100 km (39.9 – 37.9 US mpg, 47.9 – 45.6 UK mpg, 16.9 – 16.1 km/l) |
| CO2 emissions | 137-144 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 8.1 sec |
| Acceleration 0 – 62 mph | 8.1 sec |
| Acceleration 0 – 60 mph | 7.7 sec |
| Maximum speed | 231 km/h (143.54 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 8.8 kg/Hp, 113.9 Hp/tonne |
| Weight-to-torque ratio | 6 kg/Nm, 167.2 Nm/tonne |
| Power | 184 Hp @ 5000 rpm |
| Torque | 270 Nm @ 1350-4600 rpm (199.14 lb.-ft. @ 1350-4600 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | B48B20A |
| Engine displacement | 1998 cm3 (121.93 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 82 mm (3.23 in.) |
| Piston Stroke | 94.6 mm (3.72 in.) |
| Compression ratio | 11:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Twin-power turbo, Intercooler |
| Engine oil capacity | 5.25 l (5.55 US qt | 4.62 UK qt) |
| Coolant | 8.1 l (8.56 US qt | 7.13 UK qt) |
| Kerb Weight | 1615 kg (3560.47 lbs.) |
| Max. weight | 2175 kg (4795.05 lbs.) |
| Max load | 560 kg (1234.59 lbs.) |
| Trunk (boot) space – minimum | 480 l (16.95 cu. ft.) |
| Trunk (boot) space – maximum | 1300 l (45.91 cu. ft.) |
| Fuel tank capacity | 60 l (15.85 US gal | 13.2 UK gal) |
| Max. roof load | 75 kg (165.35 lbs.) |
| Permitted trailer load with brakes (12%) | 1700 kg (3747.86 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 75 kg (165.35 lbs.) |
| Length | 4640 mm (182.68 in.) |
| Width | 1825 mm (71.85 in.) |
| Height | 1404 mm (55.28 in.) |
| Wheelbase | 2810 mm (110.63 in.) |
| Front track | 1543 mm (60.75 in.) |
| Rear (Back) track | 1592 mm (62.68 in.) |
| Ride height (ground clearance) | 145 mm (5.71 in.) |
| Drag coefficient (Cd) | 0.30 |
| Minimum turning circle (turning diameter) | 11.8 m (38.71 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 8 gears, 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 |
| Tires size | 225/50 R17; 225/45 R18; 255/40 R18; 225/40 R19; 255/35 R19 |
| Wheel rims size | 7.5J x 17; 8J x 18; 8.5J x 18; 8J x 19; 8.5J x 19 |
INTRODUCTION
The BMW 420i xDrive Steptronic Gran Coupe, part of the F36 generation (2017-2021), is a four-door coupe that blends the sporty aesthetics of the 4 Series with the practicality of a sedan. Built on the BMW Group’s flexible platform, also used for the 3 Series, the Gran Coupe offers a more elegant and streamlined profile than its traditional sedan counterpart. The 420i variant, powered by a 2.0-liter turbocharged four-cylinder engine and paired with an eight-speed automatic transmission and BMW’s xDrive all-wheel-drive system, was designed to deliver a comfortable and efficient driving experience. It served as an accessible entry point into the 4 Series Gran Coupe range, appealing to buyers who prioritized refinement and all-weather capability.
Powertrain & Engine Architecture
At the heart of the 420i xDrive Steptronic lies the BMW B48B20A 2.0-liter inline-four cylinder engine. This engine utilizes direct fuel injection and a single twin-scroll turbocharger with intercooling to produce 184 horsepower at 5,000 rpm and 270 Nm (199 lb-ft) of torque between 1,350 and 4,600 rpm. The B48 engine family is known for its efficiency and responsiveness, and the 420i’s tuning prioritizes fuel economy without sacrificing acceptable performance. The engine features a 11:1 compression ratio and four valves per cylinder. The eight-speed Steptronic automatic transmission is a crucial component of this powertrain. It offers smooth and quick shifts, and features adaptive learning to optimize shift points based on driving style. The xDrive all-wheel-drive system employs a multi-plate clutch to distribute torque between the front and rear axles, enhancing traction and stability in various driving conditions.
Driving Characteristics
The 420i xDrive Steptronic delivers a composed and refined driving experience. While not as overtly sporty as the higher-powered 4 Series variants, it provides ample power for everyday driving and highway cruising. The eight-speed automatic transmission contributes to smooth acceleration, and the xDrive system provides confident handling in inclement weather. Compared to a manual transmission equipped 420i, the Steptronic offers greater convenience, particularly in urban environments. However, it may slightly diminish the driver’s sense of engagement. The gear ratios are tuned for a balance of fuel efficiency and responsiveness, with quick downshifts available when needed. The steering is precise and well-weighted, typical of BMW’s engineering philosophy.
Equipment & Trim Levels
The 420i xDrive Steptronic Gran Coupe came standard with a comprehensive list of features, including BMW’s iDrive infotainment system with a central display screen, automatic climate control, power-adjustable front seats, and a leather-wrapped steering wheel. Standard upholstery was typically a combination of cloth and leatherette. Optional extras included leather upholstery, a premium sound system, a head-up display, navigation, and various driver-assistance features such as lane departure warning and adaptive cruise control. Trim levels could vary slightly depending on the market, but generally offered packages that bundled popular options together.
Chassis & Braking
The F36 4 Series Gran Coupe features a sophisticated chassis design. The front suspension utilizes independent coil springs and struts, while the rear suspension employs an independent multi-link setup. This configuration provides a comfortable ride and precise handling. The 420i xDrive Steptronic is equipped with ventilated disc brakes on all four wheels, providing ample stopping power. The ABS (Anti-lock Braking System) is standard, along with electronic stability control and traction control. The steering system is a rack-and-pinion setup with electric power assistance.
Market Reception & Comparison
The 420i xDrive Steptronic Gran Coupe was generally well-received by automotive critics. It was praised for its stylish design, comfortable ride, and efficient powertrain. However, some reviewers noted that the 2.0-liter engine could feel somewhat underpowered compared to the larger engines available in the 4 Series lineup. Compared to the 430i and 440i models, the 420i offered a more affordable entry point into the 4 Series Gran Coupe range, but at the expense of outright performance. In terms of fuel economy, the 420i consistently outperformed its more powerful siblings. Reliability reports suggest that the B48 engine is generally robust, although routine maintenance is essential.
Legacy
The BMW 420i xDrive Steptronic Gran Coupe (F36) has established itself as a popular choice in the used car market. Its blend of style, practicality, and efficiency continues to appeal to buyers seeking a premium four-door coupe. The B48 engine has proven to be a reliable unit when properly maintained, and the eight-speed Steptronic transmission is known for its durability. While not the most exhilarating performer in the 4 Series lineup, the 420i xDrive Steptronic offers a compelling value proposition for those prioritizing comfort, refinement, and all-weather capability.
