BMW lifts lid on electric sporty

The sultry next step in the longest-running car launch in history continued yesterday with BMW revealing a convertible version of its 2014 i8 hybrid sports car. While BMW wheeled out the precursor to the i8 Coupe as far back as the 2009 Frankfurt Motor Show, its new i8 Spyder is far closer to the car's production future. The see-through glass doors have gone, replaced with a more conventional-looking pair, albeit ones that swivel up to open and have no window glass. Due to make its show debut at this month’s Beijing Motor Show, the i8 Spyder will be at the sexy end of BMW’s new i brand of fuel efficient green cars, with the smaller, all-electric i3 hatchback giving a clear indication of where BMW sees the entry point for the new lineup. BMW had always hinted that the i brand would have more to it than just the two models, and the Spyder provides the first genuine clues to how the brand’s sexiest car will work in production. Both the convertible and coupe versions of the tech-rich sports car will be built around a 'plastic' tub, reinforced with short-strand carbon-fibre, and the bodyshell is said to be made from the same ultra-strong, light-weight structure. The i8 Spyder will still tip the scales at 1630kg – but that's considerably lighter than the similarly sized 6-Series BMW. It shares much of the coupe’s distinctive silhouette, though its windscreen stands proud of the bodywork thanks to reinforced A-Pillars. While it has fixed rollover hoops that incorporate their own bodywork, a lot of the Formula One-esque aero kickers and vanes of the original coupe concept have gone. BMW has yet to indicate whether the production versions of the i8 Spyder would carry a cloth or a targa roof, though the smart money is on a clear glass lid. Speaking of which, it also runs a clear cover above the petrol engine, through which can be seen its two portable electronic kickboards, which BMW says are perfect for moving around city footpaths. BMW insists the convertible version of the fuel-sipping hybrid will still hit 100km/h in 5.0 seconds and its heart and soul remains the same combination of a three-cylinder, turbocharged petrol engine for the rear wheels and an electric motor up front to power the front wheels. Planned from its earliest briefings to be a plug-in hybrid, the i8 Spyder’s direct-injection, variable-valve timed petrol engine will pump out 164kW and 300kW – not bad from 1.5-litres. At its heart, it’s the same triple motor that is being planned for both the MINI and BMW’s upcoming front-drive range, and its all-aluminium architecture means it can be built on the same production line as BMW’s more-conventional four and six-cylinder engines. The petrol engine is backed up by a 96kW electric motor, and the i8’s powertrain combines for a total of 260kW and 550Nm. The electric motor sits between the front axles, which it will twist via a single-speed gearbox, helping the i8 Spyder to have a 50:50 front-to-rear weight distribution. The lithium-ion battery pack, housed in the central tunnel between the driver and the passenger, will fully charge in 105 minutes and BMW claims it will run up to 30km on pure electric power. That means the i8 will be capable of most typical city commutes without ever turning over its petrol engine. The i8 carries a small fuel tank for the petrol engine just behind the rear bulkhead and, besides using the internal combustion engine for added performance, it can also be fired up to act as a generator to charge the battery while the i8 Spyder is running in electric mode. The partnership of the two power plants has BMW insisting the i8 Spyder will have a combined city/highway fuel economy figure of just 3.0L/100km. With the brainpower developed in-house by BMW, the i8 Spyder is capable of being driven as either a full electric or full petrol-powered car or a combination of both. That also means it’s capable of run as a front, rear or all-wheel drive car. One major difference between the i8 Coupe and Spyder concepts is that while the Coupe is a 2+2 in the Porsche 911 style, the Spyder is a dedicated two seater with a slightly shorter wheelbase. It’s 2650mm between the centres of the petrol and electrically driven axles and is a sub 4.5-metre car, with a 4480mm overall length. It doesn’t sacrifice any width, though, with BMW saying it is 1922mm wide and only 1208mm high. It’s not all good news, though, because a 100-litre luggage area isn’t convenient for anybody, even if it does lurk behind the engine bay. Still, the i8 Coupe and Spyder are scheduled for production, based at the Leipzig plant in northern Germany, and should be in dealerships around the world from late 2014.