BMW i8 Roadster
Futuristic outlook of the plug-in hybrid sports car
The BMW i8 when launched was one of the most complex pieces of machinery ever to have graced a road going car and four years down it continues to amaze, not only because of the complex technology it embodies but because it still looks as futuristic as it did when it was first launched back in 2014. The i8 has no parallel in the world and, despite its supercar level pricing, has gone on to become the world’s largest selling plug-in hybrid sportscar. However, it was launched only as a 2+2 seater coupe and as it was time to give the car a mid-life facelift, BMW has gone ahead and added a second car to the i8 model range with the Roadster now adding to the choice.
The i8 Roadster, despite looking similar to the earlier coupe, is in fact a 2-seater sports car carrying forward a few changes from the i8 Coupe but also has upgrades all around that have also been added to the coupe. While the LifeDrive vehicle architecture with the carbon-fibre body shell remains the same, there have been upgrades to the eDrive powertrain that now has a high voltage lithium-ion battery with an expanded capacity. In addition to the i8 Coupe, is now the electrically operated all-weather fabric soft top that can be raised or lowered at the touch of a button in under 15 seconds and upto speeds of 50kmph. The top of the rear seat now makes way for the storage of the roof when folded while the lower portion is an additional 92 litres of cargo space on the roadster model.
When the soft top is lowered the rear windows are automatically raised to a preset height to minimise turbulence in the cabin. This can be further adjusted to suit the occupants. The emphasis is on keeping the car as light as possible and the standard 20-inch wheels are now each a full kilogram lighter than the lightest wheels available for the i8 before and the complex main linkages for the soft top have been printed using a hi-tech 3D printing process–futuristic technology being used in making a futuristic car.
From the outside the Roadster infact looks even more stunning than the coupe—all day, any day. The frameless gull-wing doors on the roadster add the cutting edge design of the car while the beautifully crafted Roadster emblem on the C-pillars conveys which i8 models it is, in a classy way. Upgraded LED headlamps now have a non-dazzle range of 600m. New dual colour exteriors and new alloys make up the changes
on the exteriors. In the cabin there are new seats, ceramic element inserts, the latest generation iDrive with a free-standing 8.8inch touchscreen and the option to choose a carbon-fibre trim.
But of course the biggest changes are to the drivetrain. The overall power of the hybrid system is now increased to 374bhp taking the Roadster to 100kmph from zero in 4.6 seconds and to an electronically con- trolled top speed of 250kmph. While the turbocharged 1.5-litre three-cylinder gasoline engine featuring direct injection and variable valve timing retains its maximum output of 231bhp and peak torque of 320Nm, its distinctive soundtrack has been further tuned to sound more sporty higher up in its rev range.
The engine now comes equipped with a gasoline particulate filter making the emis- sions of the i8 cars even cleaner. The electric part of the powertrain is the one that has different figures thanks to a larger battery capacity. This translates into 12bhp of more power, increasing the maximum output of the motor to 143bhp. With the increased capacity of the battery the motor contributes even more to the driving resulting in a sharper response and a cleaner drive. The range in pure electric mode is also increased to 53km
and the engine does not come on till 120kmph if one wants to drive silently, though the engineers have devised a slight sound to warn pedestrians. These upgrades to the drivetrain have been made to the coupe as well.
The joys of driving an open top seriously double when one is doing it in a car that is fun to drive, has a great performance and that can drive silently. So silent is the car that while driving in the hills of Mallorca, one could hear each chirp of the count-
less birds in the trees around and the conversation of cyclists that passed by. Initially, the chirping of the birds was so loud and intense that I thought it was being amplified through the speakers of the car. Only once I’d parked the car, switched it off, did I realise that the cacophony remained just as loud. The unique characteristics of the rear engine and front motor hybrid that one had experienced on the Coupe earlier, remain with the roadster with intensified speed and drama. Just like the Coupe the Roadster also comes with the various driving modes with change to the power delivery characteristics as well as damper tuning. While in the Eco Pro mode, the electric motor will try and take care of all driving duties and the petrol engine will cut in only when necessary (like when the charge of the battery is depleted). While in Sport mode the engine will be driving the car at all times with varying levels of assistance from the motor as and when required–still a marvellous interplay of the two powerplants.
VERDICT
The appeal of the plug-in hybrid sportscar has been multiplied manifold with the Roadster. The car not only looks as great and futuristic as the coupe but also adds to the experience, of having an open-top electric silent driving car that transforms into an extreme performance machine with combined characteristics of a motor and a high performance engine in a convertible. Since the i8 launch, the roadster has better performance, interiors and even more charm.
THE REAR ENGINE AND FRONT MOTOR HYBRID COMBO REMAIN WITH THE ROADSTER AS WELL