THE i8 hard-top certainly made a splash when it was launched three years ago. It’s seldom that a striking concept car retains so many of its design cues when the production version finally hits dealership floors. Along with its futuristic looks and attention-grabbing gullwing doors, the i8 also came with an equally forward-thinking drivetrain: a complex hybrid consisting of petrol engine, battery pack and electric motor. The design team has now taken the concept a step further, creating a Roadster version with an electrically folding soft top. So, what besides the roof is different?
Well, firstly, it obviously wasn’t merely a matter of chopping off the roof. As the entire body is made of carbon-fibre, the factory required a freshly engineered body mould. Thanks to the inherent stiffness of the i8’s shell, very little strengthening was required and the final weight gain was kept to a minimal 60 kg. The fabric-roof section is split into two and stored vertically behind the seats, reducing the space needed to house it.
The interior is much the same as the (also updated) coupé’s. There is a lightly revised dashboard, as well as a range of new trim options, including carbon-fibre elements for the facia and ceramic controls on the centre console.
The roof can be lowered in 15 seconds at vehicle speeds of up to 50 km/h, which is handy if it starts to rain or the sunshine pounds you with too many UV rays. There’s a glass rear window that can be raised to limit buffeting but the cockpit is already so snug that it doesn’t really need it. Items I found surprisingly uncomfortable were the redesigned seats; while looking great and initially feeling fine, they caused leg discomfort after a couple of hours on our launch route.
My choice for the test drive was a new E-Copper metallic-hued model and, like all Roadster variants, it had 20-inch wheels as standard. In terms of alloy design, you have a choice of turbine, propeller or rail-track-like variations.
The basic drivetrain remains the same and, as with the coupé, features a three-cylinder, 1,5-litre turbopetrol mounted at the rear, along with a front-sited electric motor. There’s also an additional 11 kW unit that functions both as a starter motor and to supply a power boost to the engine.
Although the turbopetrol unit’s output remains at 170 kW, as on the coupé, the lithium-ion batteries have increased in capacity from 7,1 kWh to 11,6 kWh, while power from the electric motor is upped by 9 kW to 105 kW (plus 250 N.m of torque). BMW quotes a pure electric range for the i8 Roadster of 53 km. The fuel tank holds 30 litres, giving you a realistic range of more than 400 km. BMW also offers an optional 42-litre tank that raises the range to 600 km.
When its electric motor is charged, the i8’s performance is certainly rapid, although not quite at the supercar levels its mid-engined body shape may suggest. It is supposed to be an ecologically advanced, efficient car for an electrified future. And that is where it shines. The i8 Roadster offers an excellent blend of power and frugality, which we can attest to considering its coupé sibling returned 5,52 L/100 km on our fuel route (which is still some way off the official manufacturer’s figure of 2,10 L/100).
Acceleration is nevertheless impressive and 0-100 km/h is dispatched in a claimed 4,6 seconds (0,2 slower than the hardtop) with the top speed limited to 250 km/h. Using the paddle shifters to flick through the six-speed gearbox only enhances that experience.
On the open road, the Roadster is as much fun to drive as the coupé. To counter the typically underwhelming sound any small-capacity turbo makes, BMW’s engineers have cheated a bit by piping in a feel-good growl prickling your ears through the sound systems. Cheat or not, it works well and harmonises with the sewing-machine whistle from the electrical componentry.
The steering has new mapping, bringing greater sensitivity round the straight ahead and, while it’s not perfect in terms of feedback, it counters with a superbly direct feel. The front-end, too, is wonderfully responsive and, overall, the i8 feels surefooted, most likely the result of changes to the suspension settings and a new vertical strut for improved wheel control.
It may have taken a while to get here – we first saw the i8 Concept Spyder at the 2012 Beijing Motor Show – but the improvements rendered to the i8 serve as a reminder of what a groundbreaking car it remains.
Ultimately, there may be faster performance cars out there for the money, but nothing comes close to the i8 in terms of its looks and tech.