The Mini Convertible (F57) facelift Cooper D 1.5, produced in 2018, represents a specific iteration within the third generation of the modern Mini Convertible. Introduced as part of the F57 lifecycle update, this model combined a fuel-efficient 1.5-liter three-cylinder diesel engine with a six-speed manual transmission. Positioned as an entry-level offering in the Convertible range, it aimed to provide a balance of affordability, economy, and the open-air driving experience characteristic of the Mini brand. This variant was primarily marketed in Europe and other regions where diesel engines remained popular, offering a compelling alternative to petrol-powered models.
Technical Specifications
| Brand | Mini |
| Model | Convertible |
| Generation | Convertible (F57, facelift 2018) |
| Type (Engine) | Cooper D 1.5 (116 Hp) |
| Start of production | 2018 |
| End of production | 2018 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 4.5-4.6 l/100 km (52.3 – 51.1 US mpg, 62.8 – 61.4 UK mpg, 22.2 – 21.7 km/l) |
| Fuel consumption (extra urban) | 3.7-3.9 l/100 km (63.6 – 60.3 US mpg, 76.3 – 72.4 UK mpg, 27 – 25.6 km/l) |
| Fuel consumption (combined) | 4.0-4.1 l/100 km (58.8 – 57.4 US mpg, 70.6 – 68.9 UK mpg, 25 – 24.4 km/l) |
| CO2 emissions | 105-109 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 | 10.7 kg/Hp, 93.1 Hp/tonne |
| Weight-to-torque ratio | 4.6 kg/Nm, 216.7 Nm/tonne |
| Power | 116 Hp @ 4000 rpm |
| Power per litre | 77.5 Hp/l |
| 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 | Turbocharger, Intercooler |
| Engine oil capacity | 4.4 l (4.65 US qt | 3.87 UK qt) |
| Coolant | 6 l (6.34 US qt | 5.28 UK qt) |
| Kerb Weight | 1246 kg (2746.96 lbs.) |
| Max. weight | 1730 kg (3814 lbs.) |
| Max load | 484 kg (1067.04 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 and type of gearbox | 6 gears, manual transmission |
| 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 |
Powertrain & Engine Architecture
The heart of the Cooper D 1.5 Convertible is the BMW Group’s B37C15A 1.5-liter inline three-cylinder diesel engine. This engine is part of the modular B-series engine family, known for its compact design and efficiency. It utilizes a turbocharger with an intercooler to boost power output, achieving 116 horsepower at 4000 rpm and 270 Nm (199 lb-ft) of torque between 1750 and 2250 rpm. The engine employs a common-rail direct fuel injection system, delivering precise fuel metering for optimal combustion. The valvetrain features four valves per cylinder, contributing to improved breathing and performance. The six-speed manual transmission provides a direct connection between the engine and the front wheels, offering drivers a more engaging driving experience compared to automatic options available on other trims.
Driving Characteristics
The 1.5-liter diesel engine, paired with the manual transmission, delivers a characteristically torquey driving experience. While not offering blistering acceleration (0-60 mph in approximately 9.4 seconds), the engine provides ample power for everyday driving and comfortable cruising. The manual gearbox allows for precise control over gear selection, enabling drivers to maximize fuel efficiency or extract more performance when needed. Compared to the more powerful Cooper S models, the Cooper D 1.5 prioritizes fuel economy and relaxed driving. The gear ratios are tuned for efficiency, with a relatively long final drive contributing to lower engine speeds at highway speeds. This results in a quieter cabin and improved fuel consumption on longer journeys.
Equipment & Trim Levels
The Cooper D 1.5 Convertible typically came equipped with a respectable 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 layout followed the classic Mini design language, featuring a centrally mounted speedometer and a multi-function display. Optional extras included navigation systems, upgraded audio systems (Harman Kardon), heated seats, and various styling packages. The Convertible-specific features, such as the fully automatic fabric roof, were standard. Trim levels were relatively simple, with options primarily focused on adding convenience and aesthetic enhancements.
Chassis & Braking
The F57 Convertible utilizes a McPherson strut front suspension and a multi-link rear suspension, providing a good balance of ride comfort and handling. The suspension setup is tuned to be slightly softer than that of the hardtop Mini models, accommodating the reduced structural rigidity of the convertible body. Braking duties are handled by ventilated discs at the front and solid discs at the rear, equipped with ABS (Anti-lock Braking System). The steering is electrically assisted, providing precise and responsive control. The relatively low curb weight of 1246 kg (2746.96 lbs) contributes to the car’s nimble handling characteristics.
Market Reception & Comparison
The Cooper D 1.5 Convertible was generally well-received by critics as an affordable and economical entry point into the Mini Convertible range. Its fuel efficiency was a major selling point, particularly in Europe where diesel fuel was often cheaper than petrol. However, some reviewers noted that the engine lacked the outright performance of the more powerful Cooper S models. Compared to the petrol-powered Cooper models, the Cooper D 1.5 offered superior fuel economy but a less exciting driving experience. Reliability was generally good, with the B37 engine proving to be a robust and dependable unit.
Legacy
The Cooper D 1.5 Convertible, while not the most sought-after variant, remains a viable option in the used car market. The B37 engine has proven to be relatively reliable, although regular maintenance is crucial, particularly regarding the diesel particulate filter (DPF). These models offer a unique combination of Mini’s iconic styling, open-air driving enjoyment, and impressive fuel economy. As with any used car, a thorough inspection is recommended before purchase, paying particular attention to the condition of the roof mechanism and the DPF system. The 2018 facelifted model benefits from improvements made during the F57’s lifecycle, making it a more refined and well-equipped option compared to earlier versions.
