The Mini Convertible (F57) Cooper SD 2.0 Steptronic, produced from 2018, represents a diesel-powered variant within the facelifted third generation of the Mini Convertible. Positioned as a mid-range offering, it aimed to provide a balance between fuel efficiency, respectable performance, and the open-air driving experience characteristic of the Mini Convertible. This model year saw a refresh of the F57 platform (introduced in 2016), incorporating styling updates and technological enhancements. The Cooper SD 2.0 Steptronic specifically targeted buyers seeking a more economical alternative to the petrol-powered Cooper and Cooper S models, while still offering a premium driving experience.
Technical Specifications
| Brand | Mini |
| Model | Convertible |
| Generation | Convertible (F57, facelift 2018) |
| Type (Engine) | Cooper SD 2.0 (170 Hp) Steptronic |
| Start of production | 2018 |
| End of production | 2018 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 4.9-5.0 l/100 km (48 – 47 US mpg, 57.6 – 56.5 UK mpg, 20.4 – 20 km/l) |
| Fuel consumption (extra urban) | 3.9-4.1 l/100 km (60.3 – 57.4 US mpg, 72.4 – 68.9 UK mpg, 25.6 – 24.4 km/l) |
| Fuel consumption (combined) | 4.3-4.4 l/100 km (54.7 – 53.5 US mpg, 65.7 – 64.2 UK mpg, 23.3 – 22.7 km/l) |
| CO2 emissions | 113-116 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 7.7 sec |
| Acceleration 0 – 62 mph | 7.7 sec |
| Acceleration 0 – 60 mph | 7.3 sec |
| Maximum speed | 218 km/h (135.46 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 7.7 kg/Hp, 130.3 Hp/tonne |
| Weight-to-torque ratio | 3.6 kg/Nm, 275.9 Nm/tonne |
| Power | 170 Hp @ 4000 rpm |
| Torque | 360 Nm @ 1500-2750 rpm (265.52 lb.-ft. @ 1500-2750 rpm) |
| Engine layout | Front, Transverse |
| Engine Model/Code | B47C20B |
| 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 | Turbocharger, Intercooler |
| Engine oil capacity | 5 l (5.28 US qt | 4.4 UK qt) |
| Coolant | 7 l (7.4 US qt | 6.16 UK qt) |
| Kerb Weight | 1305 kg (2877.03 lbs.) |
| Max. weight | 1770 kg (3902.18 lbs.) |
| Max load | 465 kg (1025.15 lbs.) |
| Trunk (boot) space – minimum | 160 l (5.65 cu. ft.) |
| Trunk (boot) space – maximum | 215 l (7.59 cu. ft.) |
| Fuel tank capacity | 44 l (11.62 US gal | 9.68 UK gal) |
| Length | 3850 mm (151.57 in.) |
| Width | 1727 mm (67.99 in.) |
| Height | 1415 mm (55.71 in.) |
| Wheelbase | 2495 mm (98.23 in.) |
| Front track | 1485 mm (58.46 in.) |
| Rear (Back) track | 1485 mm (58.46 in.) |
| Ride height (ground clearance) | 115 mm (4.53 in.) |
| Drag coefficient (Cd) | 0.36 |
| Minimum turning circle | 10.8 m (35.43 ft.) |
| Drivetrain Architecture | Front wheel drive |
| Number of gears and type of gearbox | 6 gears, automatic transmission Steptronic |
| Front suspension | Independent, type McPherson with coil spring and anti-roll bar |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
Powertrain & Engine Architecture
The Cooper SD 2.0 Steptronic is powered by the BMW Group’s B47C20B engine, a 2.0-liter inline-four cylinder diesel. This engine is a member of the modular B-series engine family, known for its efficiency and refinement. The B47 utilizes a common-rail direct injection system, delivering fuel at extremely high pressures for optimized combustion. A single turbocharger with an intercooler provides forced induction, boosting power and torque. The engine features four valves per cylinder and a sophisticated engine management system to balance performance and fuel economy. The “Steptronic” transmission is a six-speed automatic gearbox, offering smooth shifts and adaptive learning capabilities. This transmission is designed to optimize fuel efficiency and provide a comfortable driving experience.
Driving Characteristics
The 170 hp and 360 Nm (265 lb-ft) of torque delivered by the Cooper SD 2.0 Steptronic provided a noticeable step up in performance compared to the base Cooper models. Acceleration from 0-60 mph took approximately 7.3 seconds, making it a reasonably quick vehicle for everyday driving. The automatic transmission, while convenient, did slightly diminish the sense of engagement compared to the available manual gearbox. The torque curve was relatively flat, providing good responsiveness across a wide range of engine speeds. However, the diesel engine lacked the immediate throttle response and high-revving character of the petrol-powered Mini variants. The Steptronic transmission’s gear ratios were tuned for fuel efficiency, which sometimes resulted in the engine feeling slightly strained during aggressive acceleration.
Equipment & Trim Levels
The Cooper SD 2.0 Steptronic typically came equipped with a generous level of standard features. These included air conditioning, power windows, a multi-function steering wheel, and a Mini infotainment system with a central display screen. Upholstery was generally cloth, with leather options available as an upgrade. Optional extras included navigation, a premium sound system, parking sensors, and various styling packages. The convertible top was fully automatic and could be operated at speeds up to 30 mph. Trim levels beyond the base Cooper SD offered additional features such as sport seats, upgraded interior trim, and exterior styling enhancements.
Chassis & Braking
The F57 Convertible utilized a McPherson strut front suspension and a multi-link rear suspension, providing a good balance between ride comfort and handling. The suspension was tuned to be slightly softer than the standard Mini hatchback to accommodate the convertible’s increased weight and reduced structural rigidity. Front brakes were ventilated discs, while rear brakes were solid discs. Anti-lock Braking System (ABS) and Electronic Stability Control (ESC) were standard safety features. The steering was electric power-assisted, offering precise control and a responsive feel.
Market Reception & Comparison
The Cooper SD 2.0 Steptronic was generally well-received by automotive critics. It was praised for its fuel efficiency, comfortable ride, and refined engine. However, some reviewers noted that the diesel engine lacked the character and excitement of the petrol-powered models. Compared to the Cooper, the SD offered significantly better fuel economy and more torque. Compared to the Cooper S, it sacrificed some performance but provided a more affordable and economical option. Reliability was generally good, although diesel engines can be more susceptible to issues with the particulate filter and fuel injection system if not properly maintained.
Legacy
The B47 engine family, including the B47C20B found in the Cooper SD, has proven to be a relatively reliable powertrain when properly maintained. Common issues include diesel particulate filter (DPF) clogging, particularly with frequent short trips, and potential fuel injector problems. On the used car market, the Cooper SD 2.0 Steptronic represents a good value proposition for buyers seeking a fuel-efficient and stylish convertible. Its combination of performance, economy, and practicality has ensured its continued appeal in the years since its production ended.
