The Mini Convertible (F57) Cooper D 1.5 (116 hp) Steptronic was a diesel-powered variant of the third-generation Mini Convertible, produced between 2016 and 2018. Positioned as an entry-level to mid-range offering within the F57 lineup, it aimed to provide a balance of fuel efficiency and open-top motoring. This model represented Mini’s continued effort to broaden the appeal of the Convertible, offering a more economical alternative to the petrol-powered Cooper and Cooper S versions. It was primarily marketed in Europe and other regions where diesel fuel was prevalent, offering a compelling option for drivers seeking lower running costs without sacrificing the iconic Mini experience.
Technical Specifications
| Brand | Mini |
| Model | Convertible |
| Generation | Convertible (F57) |
| Type (Engine) | Cooper D 1.5 (116 Hp) Steptronic |
| Start of production | 2016 |
| End of production | 2018 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 4.5-4.4 l/100 km (52.3 – 53.5 US mpg) |
| Fuel consumption (extra urban) | 3.9-3.7 l/100 km (60.3 – 63.6 US mpg) |
| Fuel consumption (combined) | 4.1-3.9 l/100 km (57.4 – 60.3 US mpg) |
| CO2 emissions | 109-104 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 9.9 sec |
| Acceleration 0 – 62 mph | 9.9 sec |
| Acceleration 0 – 60 mph | 9.4 sec |
| Maximum speed | 195 km/h (121.17 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 10.3 kg/Hp |
| Weight-to-torque ratio | 4.4 kg/Nm |
| Power | 116 Hp @ 4000 rpm |
| Torque | 270 Nm @ 1750-2250 rpm (199.14 lb.-ft. @ 1750-2250 rpm) |
| Engine layout | Front, Transverse |
| Engine Model/Code | B37C15A |
| Engine displacement | 1496 cm3 (91.29 cu. in.) |
| Number of cylinders | 3 |
| 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 | 4.4 l (4.65 US qt | 3.87 UK qt) |
| Coolant | 3.3 l (3.49 US qt | 2.9 UK qt) |
| Kerb Weight | 1190 kg (2623.5 lbs.) |
| Max. weight | 1730 kg (3814 lbs.) |
| Max load | 540 kg (1190.5 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 | 3821 mm (150.43 in.) |
| Width | 1727 mm (67.99 in.) |
| Height | 1415 mm (55.71 in.) |
| Wheelbase | 2495 mm (98.23 in.) |
| Front track | 1501 mm (59.09 in.) |
| Rear (Back) track | 1501 mm (59.09 in.) |
| Ride height (ground clearance) | 115 mm (4.53 in.) |
| Drag coefficient (Cd) | 0.33 |
| Minimum turning circle | 10.8 m (35.43 ft.) |
| Drivetrain Architecture | Front wheel drive |
| Number of gears | 6 |
| Gearbox type | 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 |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 175/65 R15 84H |
| Wheel rims size | 5.5J x 15 |
INTRODUCTION
The F57 Mini Convertible, launched in 2016, represented the third generation of Mini’s open-top model. The Cooper D 1.5 Steptronic variant, powered by a 1.5-liter three-cylinder diesel engine producing 116 horsepower, was a key component of the range. Built on the UKL1 platform (shared with other BMW Group vehicles), the F57 offered improved space and refinement over its predecessor. The Cooper D 1.5 Steptronic aimed to appeal to buyers prioritizing fuel economy and relaxed cruising in a stylish package. Production of this specific configuration ran from 2016 to 2018, before being superseded by later iterations of the F57.
Powertrain & Engine Architecture
At the heart of the Cooper D 1.5 Steptronic lies the BMW Group’s B37C15A engine. This 1.5-liter inline-three cylinder diesel engine utilizes a single turbocharger and direct injection, delivering 116 hp at 4000 rpm and 270 Nm (199 lb-ft) of torque between 1750 and 2250 rpm. The engine features a common rail diesel injection system operating at very high pressures to optimize combustion. The valvetrain employs four valves per cylinder, enhancing breathing and efficiency. The engine is transversely mounted at the front of the vehicle. The “Steptronic” transmission refers to a six-speed automatic gearbox, offering smooth shifts and contributing to the car’s ease of driving. This transmission is known for its adaptive learning capabilities, adjusting shift points based on driving style.
Driving Characteristics
The 116 hp output and automatic transmission of the Cooper D 1.5 Steptronic resulted in a driving experience focused on comfort and efficiency rather than outright performance. Acceleration from 0 to 62 mph took approximately 9.9 seconds, and top speed was limited to 195 km/h (121 mph). While not as brisk as the Cooper or Cooper S models, the diesel engine provided ample torque for everyday driving, making overtaking and hill climbs manageable. The automatic transmission, while smooth, could sometimes feel hesitant during quick downshifts. Compared to the six-speed manual version, the automatic offered greater convenience, particularly in urban environments, but at the expense of some driver engagement. The gear ratios were tuned for fuel economy, prioritizing higher gears at cruising speeds.
Equipment & Trim Levels
The Cooper D 1.5 Steptronic typically came equipped with a reasonable level of standard features. These included air conditioning, power windows, central locking, and a basic audio system. Interior upholstery was generally cloth, with options for leather upgrades. The dashboard featured Mini’s signature circular central display, providing access to infotainment functions. Optional extras included navigation, a premium sound system, parking sensors, and various styling packages. Trim levels could vary depending on the market, but generally, the Cooper D 1.5 Steptronic sat in the middle of the range, offering a step up from the base model in terms of equipment but lacking the more luxurious features of the Cooper S.
Chassis & Braking
The F57 Mini Convertible utilized a McPherson strut front suspension and a multi-link rear suspension, providing a good balance of ride comfort and handling. The Cooper D 1.5 Steptronic, being a lower-powered variant, typically featured smaller diameter wheels and tires compared to the Cooper S. Front brakes were ventilated discs, while rear brakes were solid discs. Anti-lock Braking System (ABS) was standard. The suspension was tuned to provide a comfortable ride, but the car still exhibited the characteristic Mini go-kart handling, albeit in a more subdued form than the higher-performance models. Stabilizer bars were fitted front and rear to reduce body roll during cornering.
Market Reception & Comparison
The Cooper D 1.5 Steptronic was generally well-received by critics as a practical and economical option within the Mini Convertible range. Its fuel economy figures – around 57.4-60.3 mpg (US) – were a major selling point. Compared to the petrol-powered Cooper, the diesel offered significantly lower running costs, making it an attractive choice for high-mileage drivers. However, some reviewers noted that the diesel engine lacked the refinement and responsiveness of the petrol alternatives. The automatic transmission also drew some criticism for its occasional hesitancy. In terms of reliability, the B37 engine proved to be generally robust, although diesel particulate filter (DPF) issues could occur with infrequent long journeys.
Legacy
The Mini Convertible (F57) Cooper D 1.5 Steptronic remains a relatively common sight on the used car market. The B37 engine, while not without its potential issues (particularly related to the DPF), has proven to be reasonably durable with proper maintenance. These models offer a stylish and economical way to experience open-top motoring. Their relatively low running costs and the enduring appeal of the Mini brand continue to make them a popular choice for buyers seeking a fun and practical convertible. However, potential buyers should be aware of the potential for DPF problems and ensure the car has been regularly serviced.
