The BMW 4 Series Convertible (F33), specifically the 430d variant with the Steptronic automatic transmission, was produced from 2017 to 2020 as part of the F33 LCI (Life Cycle Impulse – BMW’s term for facelift) generation. This model occupied a mid-range position within the 4 Series Convertible lineup, offering a balance between performance, fuel efficiency, and luxury features. It represented BMW’s continued commitment to the premium compact convertible segment, appealing to buyers seeking a refined open-top driving experience with a diesel powertrain. The F33 generation, built on the BMW F30 platform, aimed to blend sporty handling with everyday usability.
Technical Specifications
| Brand | BMW |
| Model | 4 Series |
| Generation | 4 Series Convertible (F33, facelift 2017) |
| Type (Engine) | 430d (258 Hp) Steptronic |
| Start of production | 2017 |
| End of production | 2020 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 6.1-6.3 l/100 km (38.6 – 37.3 US mpg, 46.3 – 44.8 UK mpg, 16.4 – 15.9 km/l) |
| Fuel consumption (extra urban) | 4.8-5.0 l/100 km (49 – 47 US mpg, 58.9 – 56.5 UK mpg, 20.8 – 20 km/l) |
| Fuel consumption (combined) | 5.3-5.5 l/100 km (44.4 – 42.8 US mpg, 53.3 – 51.4 UK mpg, 18.9 – 18.2 km/l) |
| CO2 emissions | 139-144 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 5.9 sec |
| Acceleration 0 – 62 mph | 5.9 sec |
| Acceleration 0 – 60 mph | 5.6 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 6.9 kg/Hp, 145.8 Hp/tonne |
| Weight-to-torque ratio | 3.2 kg/Nm, 316.4 Nm/tonne |
| Power | 258 Hp @ 4000 rpm |
| Torque | 560 Nm @ 1500-3000 rpm (413.03 lb.-ft. @ 1500-3000 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | N57D30A |
| 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 | 7.2 l (7.61 US qt | 6.34 UK qt) |
| Kerb Weight | 1770 kg (3902.18 lbs.) |
| Max. weight | 2220 kg (4894.26 lbs.) |
| Max load | 450 kg (992.08 lbs.) |
| Trunk (boot) space – minimum | 370 l (13.07 cu. ft.) |
| Fuel tank capacity | 57 l (15.06 US gal | 12.54 UK gal) |
| 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 | 4640 mm (182.68 in.) |
| Width | 1825 mm (71.85 in.) |
| Height | 1384 mm (54.49 in.) |
| Wheelbase | 2810 mm (110.63 in.) |
| Front track | 1544 mm (60.79 in.) |
| Rear (Back) track | 1593 mm (62.72 in.) |
| Ride height (ground clearance) | 130 mm (5.12 in.) |
| Drag coefficient (Cd) | 0.29 |
| Minimum turning circle (turning diameter) | 11.3 m (37.07 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 | Independent coil spring |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
Powertrain & Engine Architecture
The heart of the 430d Convertible is the BMW N57D30A 3.0-liter inline-six diesel engine. This engine is a member of the highly regarded N57 family, known for its robust construction and refined power delivery. The N57D30A utilizes a common-rail direct injection system, injecting fuel at extremely high pressures to optimize combustion efficiency and reduce emissions. It’s equipped with a twin-scroll turbocharger and an intercooler, boosting power output to 258 horsepower and 413 lb-ft of torque. The engine’s torque curve is particularly noteworthy, providing strong pulling power from as low as 1500 rpm. The Steptronic 8-speed automatic transmission is integral to the driving experience. This transmission features smooth, quick shifts and adaptive learning, adjusting shift points based on driving style. It also includes paddle shifters for manual control when desired.
Driving Characteristics
The 430d Convertible with the Steptronic transmission delivers a refined and comfortable driving experience. While not as overtly sporty as some of its gasoline-powered siblings, the 430d offers ample power for confident overtaking and cruising. The automatic transmission is well-matched to the engine’s torque characteristics, providing seamless acceleration. Compared to the 420d, the 430d offers a noticeable performance upgrade, while remaining more fuel-efficient than the 440i. The gear ratios are tuned for a balance of acceleration and fuel economy, with taller gears for relaxed highway cruising. The rear-wheel-drive configuration contributes to balanced handling, although it can require more careful throttle control in slippery conditions.
Equipment & Trim Levels
The 430d Convertible typically came well-equipped as standard. Common features included leather upholstery, automatic climate control, a BMW iDrive infotainment system with a central display screen, and a premium sound system. Optional extras included features like a head-up display, adaptive cruise control, a Harman Kardon surround sound system, and various interior trim options. The convertible top was fully automatic and could be operated at speeds up to a certain limit. Trim levels varied by market, but generally offered packages that bundled popular options together.
Chassis & Braking
The F33 4 Series Convertible utilizes a sophisticated chassis design. The front suspension features independent coil springs, while the rear employs an independent multi-link setup. This configuration provides a good balance of ride comfort and handling precision. The 430d typically came equipped with ventilated disc brakes on all four wheels, providing ample stopping power. Anti-lock braking system (ABS) and electronic stability control (ESC) were standard safety features. The suspension tuning was generally geared towards comfort, but offered a sporty feel with minimal body roll during cornering.
Market Reception & Comparison
The 430d Convertible was generally well-received by automotive critics. It was praised for its refined engine, comfortable ride, and stylish design. The diesel engine’s fuel efficiency was a significant selling point, particularly in European markets where diesel fuel is more common and often less expensive than gasoline. Compared to the 420d, the 430d offered a worthwhile performance upgrade for those willing to spend a bit more. Against the 440i, the 430d provided a more economical option without sacrificing too much in terms of driving enjoyment. Some critics noted that the diesel engine lacked the aural excitement of the gasoline engines.
Legacy
The N57D30A engine has proven to be a durable and reliable powerplant, with many examples exceeding high mileage with proper maintenance. The 430d Convertible remains a popular choice in the used car market, offering a compelling combination of style, performance, and fuel efficiency. However, potential buyers should be aware of the potential for diesel particulate filter (DPF) issues, particularly on vehicles that have primarily been used for short trips. Regular servicing and the use of high-quality diesel fuel are essential for maintaining the long-term reliability of this powertrain. The F33 generation 4 Series Convertible, and the 430d variant in particular, represents a refined and capable entry into the premium convertible segment.
