Technical Specifications
| Brand | BMW |
| Model | 4 Series |
| Generation | 4 Series Coupe (G22) |
| Type (Engine) | 420i (184 Hp) Steptronic |
| Start of production | 2020 |
| End of production | January, 2024 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 4 |
| Doors | 2 |
| Combined fuel consumption (WLTP) | 6.3-7.1 l/100 km (37.3 – 33.1 US mpg, 44.8 – 39.8 UK mpg, 15.9 – 14.1 km/l) |
| CO2 emissions (WLTP) | 143-161 g/km |
| Fuel consumption (economy) – urban (NEDC) | 6.6-7.2 l/100 km (35.6 – 32.7 US mpg, 42.8 – 39.2 UK mpg, 15.2 – 13.9 km/l) |
| Fuel consumption (economy) – extra urban (NEDC) | 4.6-5.0 l/100 km (51.1 – 47 US mpg, 61.4 – 56.5 UK mpg, 21.7 – 20 km/l) |
| Fuel consumption (economy) – combined (NEDC) | 5.3-5.8 l/100 km (44.4 – 40.6 US mpg, 53.3 – 48.7 UK mpg, 18.9 – 17.2 km/l) |
| CO2 emissions (NEDC) | 122-132 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 7.5 sec |
| Acceleration 0 – 62 mph | 7.5 sec |
| Acceleration 0 – 60 mph | 7.1 sec |
| Maximum speed | 240 km/h (149.13 mph) |
| Emission standard | EURO 6d |
| Weight-to-power ratio | 8.3 kg/Hp, 120.7 Hp/tonne |
| Weight-to-torque ratio | 5.1 kg/Nm, 196.7 Nm/tonne |
| Power | 184 Hp @ 5000-6500 rpm |
| Power per litre | 92.1 Hp/l |
| Torque | 300 Nm @ 1350-4000 rpm (221.27 lb.-ft. @ 1350-4000 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 |
| Valvetrain | VALVETRONIC |
| Engine oil capacity | 5.25 l (5.55 US qt | 4.62 UK qt) |
| Coolant | 10 l (10.57 US qt | 8.8 UK qt) |
| Kerb Weight | 1525 kg (3362.05 lbs.) |
| Max. weight | 2015 kg (4442.31 lbs.) |
| Max load | 490 kg (1080.27 lbs.) |
| Trunk (boot) space – minimum | 440 l (15.54 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 | 4768 mm (187.72 in.) |
| Width | 1852 mm (72.91 in.) |
| Width including mirrors | 2081 mm (81.93 in.) |
| Height | 1383 mm (54.45 in.) |
| Wheelbase | 2851 mm (112.24 in.) |
| Front track | 1575 mm (62.01 in.) |
| Rear (Back) track | 1611 mm (63.43 in.) |
| Front overhang | 858 mm (33.78 in.) |
| Rear overhang | 1059 mm (41.69 in.) |
| Ride height (ground clearance) | 127 mm (5 in.) |
| Drag coefficient (Cd) | 0.25 |
| Minimum turning circle (turning diameter) | 11.4 m (37.4 ft.) |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| 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 | 225/50 R17 98Y XL |
| Wheel rims size | 7.5J x 17 |
The BMW 420i Steptronic, launched in 2020 as part of the G22 4 Series Coupe range, aimed to deliver the core BMW driving experience to a wider audience. It served as the entry-level model, offering a more affordable and fuel-efficient alternative to the more powerful 430i and M440i variants. The G22 generation represented a significant departure in styling from its predecessor (F32), adopting a bolder, more angular design language. The 420i’s positioning was crucial for attracting buyers who prioritized style, comfort, and efficiency over outright performance, making it a popular choice in both European and North American markets.
Powertrain & Engine Architecture
At the heart of the 420i lies BMW’s B48B20A 2.0-liter turbocharged inline-four cylinder engine. This engine is a member of BMW’s modular engine family, known for its efficiency and refinement. It utilizes direct fuel injection, a twin-scroll turbocharger, and BMW’s VALVETRONIC variable valve timing and lift system. VALVETRONIC allows for precise control of valve timing and lift, optimizing engine performance and fuel economy across a wide range of driving conditions. The engine produces 184 horsepower at 5000-6500 rpm and 300 Nm (221 lb-ft) of torque between 1350 and 4000 rpm.
The “Steptronic” designation refers to BMW’s 8-speed automatic transmission. This transmission is known for its smooth and quick shifts, contributing to both performance and fuel efficiency. It features a torque converter and allows for both automatic and manual gear selection via steering wheel-mounted paddles or the gear selector. The transmission is programmed for comfort and efficiency in typical driving situations, but can quickly downshift when more power is needed.
Driving Characteristics
The 420i Steptronic delivers a comfortable and refined driving experience. While not as overtly sporty as the 430i or M440i, it still offers a respectable level of performance. Acceleration from 0-60 mph takes approximately 7.1 seconds, and the car has a top speed of 149 mph. The 8-speed automatic transmission is well-matched to the engine, providing smooth and seamless gear changes. The gear ratios are optimized for fuel efficiency, but the transmission will readily downshift when requested. Compared to the manual transmission option (available in some markets), the Steptronic offers greater convenience and ease of use, particularly in urban driving. However, some enthusiasts may find the manual transmission more engaging.
Equipment & Trim Levels
The 420i typically came standard with a comprehensive list of features, including BMW’s iDrive infotainment system with a 8.8-inch touchscreen display, Apple CarPlay and Android Auto compatibility, automatic climate control, and a suite of driver-assistance systems such as lane departure warning and forward collision warning. Interior upholstery was typically a combination of Sensatec (synthetic leather) and cloth. Optional extras included leather upholstery, a premium sound system, a head-up display, and adaptive suspension. Trim levels varied slightly by market, but generally offered packages that bundled popular options together.
Chassis & Braking
The 420i utilizes a double-wishbone front suspension and an independent multi-link rear suspension, providing a comfortable and controlled ride. The suspension is tuned for a balance between comfort and handling. Brakes are ventilated discs all around, providing ample stopping power. ABS (Anti-lock Braking System) is standard. The 420i’s weight of approximately 3362 lbs is relatively well-distributed, contributing to balanced handling characteristics.
Market Reception & Comparison
The 420i Steptronic was generally well-received by automotive critics. It was praised for its comfortable ride, refined engine, and fuel efficiency. However, some reviewers noted that the engine could feel slightly underpowered, particularly when fully loaded or driving uphill. Compared to the 430i, the 420i offered a more affordable entry point into the 4 Series lineup, but at the expense of some performance. Fuel economy was a strong point, with combined fuel consumption figures ranging from 33.1 to 37.3 US mpg. Reliability has been generally good, with few widespread issues reported.
Legacy
The BMW 420i Steptronic represents a solid offering in the entry-level luxury coupe segment. The B48 engine has proven to be a reliable and durable powerplant, and the 8-speed Steptronic transmission is known for its smooth operation. On the used car market, the 420i offers a good value proposition, providing a stylish and well-equipped coupe at a relatively affordable price. Maintenance costs are generally reasonable, although as with any luxury vehicle, preventative maintenance is key to long-term reliability. The G22 4 Series, including the 420i, has established itself as a popular choice for buyers seeking a blend of style, comfort, and driving enjoyment.
