MINI Cooper Convertible

Electric soft top that can be opened and closed in approximately 20 seconds

An attractive “convertible” version has been added to the MINI, which is popular in Japan. The first MINI, which became part of the BMW Group, debuted in 2001. At the time, it was approximately 3.6 meters long, roughly the same size as the first Mercedes-Benz A-Class. It was released on the Japanese market on March 2, 2002, and the first convertible was released in 2004, featuring an electric soft top.

At the time, the main technical challenge was body rigidity and crash safety for convertibles. My family also owned a MINI soft top, and the soft top, which was both a hobby and a practical item, had an outstanding presence, and even though it was an open-top car, the body never shook violently when driving.

MINI is produced at the Oxford plant in the UK. When I visited the plant some time ago, I was surprised to see that the MINI body was made without being bound by conventional wisdom. Even back then, go-kart-like handling was a distinctive feature of the MINI, so the engineers considered body rigidity to be extremely important. It goes without saying that BMW’s technology was put to good use here.

With a soft-top convertible, you can’t just chop off the roof and call it a day. Naturally, the lack of a roof reduces the body’s rigidity. Therefore, MINI has reinforced the area from the floor to the side sills to ensure body rigidity even without a roof, ensuring torsional rigidity. Furthermore, the A-pillars have been reinforced and an aluminum roll bar has been added. Safety has also been improved in the event of a side collision by strengthening the doors. This has resulted in an increase in weight of approximately 130 kg, but the soft-top of the new Cooper Convertible S that I test drove this time weighs only 100 kg less. Over the past 20 years, soft-tops have also become lighter.

The 240mm glass center display has a modern design

The iconic 240mm glass center display is also featured on the convertible, and the electric soft top can be fully opened in approximately 20 seconds and closed in approximately 15 seconds. — [1]

The test drive took place at a BMW customer center in South Carolina in the southern United States. The Cooper Convertible S I drove was a model equipped with a 204 PS 2.0-liter 4-cylinder turbo engine. While a diesel engine is also available in Europe, gasoline vehicles are the norm in the United States. American MINI enthusiasts tend to prefer soft-top cars, and apparently enjoy driving open-top cars even in cold climates.

I immediately turned on the electric soft top to try it out. It can be opened and closed while driving at speeds below 30km/h, so I was able to easily try opening and closing it. It takes about 20 seconds to fully open it, giving me a sense of openness. The test drive was in November, so it was cold, but the seat heaters kept me warm. If I can’t stand the cold, there’s also a sunroof mode that opens the roof by just 40cm, so I was able to easily enjoy the feeling of openness.

Choose the perfect Pirelli tire

The Cooper Convertible S was fitted with Pirelli Cinturato P7 tires, which offered excellent grip balance.

The gearbox is a DCT, just like the Cooper S, and you can enjoy a snappy gear shift. Now, with the soft top, what I’m most interested in is the ride comfort and handling. I wasn’t able to drive it on a circuit, but I checked it out on the freeway and country roads. I’ve already test driven the Cooper S in Japan, and compared to the Cooper Convertible S, I didn’t get the impression that the body rigidity was lower; rather, the increased weight means that the body absorbs small vibrations. This may be why road noise felt so low.

We got off the freeway and drove on a country road, where the road surface was rough in places. Thinking that this would be a good place to evaluate the ride comfort, we drove on it several times. The video on the attached iPhone also showed that there was little shaking. The suspension absorbed the uneven road surface well. MINI claims to offer go-kart-like driving, so the suspension is on the stiff side, but the damping that feels one with the body is the essence of MINI. It will be introduced in Japan in 2025, but as there are few soft-top models in this class, it is likely to be a valuable car.

Produced at the Oxford factory in the UK

The MINI Cooper Convertible has a cool and cute design even when open. It will no doubt be popular in Japan as well.

REPORT/Kazuo SHIMIZU

PHOTO/BMW AG

MAGAZINE/ GENROQ March 2025 issue

SPECIFICATIONS

MINI Cooper Convertible S

Body size: Length 3880, Width 1745, Height 1435mm

Wheelbase: 2495mm

Engine: Inline 4-cylinder DOHC turbo

Total displacement: 1998cc

Maximum output: 154kW (204PS) / 5000rpm

Maximum torque: 300Nm (30.6kgm) / 1450-4500rpm

Transmission: 7-speed DCT

Drive system: FWD

Suspension: Front MacPherson strut, rear multi-link

Brakes: Front and rear ventilated disc

Tire size: Front and rear 215/45R17

Vehicle price: 5.14 million yen