IT’S the doors that elicit the most animated reaction from wide-eyed onlookers. If the first sight of BMW’s striking i8 is the part in the movie where audiences sit forward in their seats, the moment the scissor doors open to lift above the roofline is when they drop their popcorn.
It’s a response unlike any we’ve experienced with a vehicle before and the CAR team has been behind the wheel of some exotic machinery. Now, six years after BMW first unveiled its show-stopping Vision EfficientDynamics – a concept that boldly imagined the future of the sportscar – the production i8 hybrid represents a sleek, exquisitely detailed working example of this thinking.
With its doors open, you’re greeted with large sections of exposed carbon-fibre on the wide sills and door linings. Unlike the likes of McLaren’s 650S, BMW has purposefully chosen not to apply a polished gleam to its surface, rather leaving the raw carbon-fibre to remind you of its extensive use within in the i8’s construction and so emphasising the lengths to which BMW has gone to ensure both maximum rigidity and lightweight efficiency. In engineering a more cost-effective way of manipulating this high-strength material, BMW has developed its LifeDrive passenger cell (including doors) to fasten onto the all-aluminium chassis below.
While there’s no glamorous way of sliding over the wide sill and into the i8’s cockpit, once inside a welcome amount of adjustment on the front seats and steering column affords drivers of all shapes and sizes a comfortable and suitably low-slung seating position. Despite the futuristic exterior styling, there’s a welcome familiarity to the cabin’s functionality and, in this application in particular, trim levels are neat and as form hugging as a tailored suit. A suit so well fitted, it has to be said, that there’s little or no room left for small-item storage.
It seems a strange decision to include rear seats, but their presence (while very compromised in terms of comfort) will appeal to owners keen on instant-hero-status school runs. With only a small 96 dm3 luggage compartment available aft of the engine bay, we guess these rear seats might also be used for overflow packages.
Still, answering questions around the possible functionality of those rear seats is the easy bit; it gets complicated when explaining what happens underneath all that aluminium and carbon-fibre.
Fielding inevitable questions about what high-performance internal-combustion engine may be housed within such an alluring and svelte body, we would advise prospective South African i8 owners to focus less on its overall capacity (a mere 1,5 litres) and number of cylinders (three), and more on the fact that this engine delivers more power per litre than any modern BMW.
It’s an engine shared with the current Mini Cooper and, mounted transversely at the rear of the i8, features a turbocharger set to 1,7 bar to deliver 170 kW at 5 800 r/min and 320 N.m of torque at 3 700 r/min. This lightweight powertrain drives the rear wheels via a six-speed (rather than eight) automatic transmission and is mated with a dual-function 11 kW electric motor that acts both as the starter motor and can fill in holes caused by turbo lag.
That’s the simple part.
Mounted within the i8’s nose and exclusively turning the front wheels is a 96 kW/250 N.m electric motor. Powered by plug-in-rechargeable 7,1 kWh lithium-ion batteries installed below the passenger cell, this unit is able to pull the i8 along in zero-emissions silence to a maximum speed of 120 km/h for up to 35 km. Ask more of this motor than the reserves that are available (whether due to insufficient charge or power), and the i8’s clever systems seamlessly call upon the petrol engine for assistance. Despite there being no mechanical connection between the front and rear wheels, the i8 is thus effectively all-wheel driven.
Depress the starter button and the default drive mode is comfort. Here, based on driver input, the system decides whether the i8 needs to be pushed or pulled. Select Eco Pro mode and a dulling of the throttle response, together with stifled climate-control settings, can add a further 20% (around 100 km) to the tank range while still using both power supplies.
The aforementioned all-electric mode is available at the press of a button, but shifting the gear selector to the left calls all systems, petrol and electric, to their most heightened states of tune. In this sport mode – signalled by a change in lighting of the digital instrumentation from blue to red and piping in an artificial, V6-inspired exhaust note through the audio system – the i8 can call upon a combined 266 kW and 570 N.m, affording it the best opportunity of living up to its hypercar-like presence. A two-speed transmission on the electric motor (geared 11,3 and 5,85 to 1) allows the transition between front- and rear-wheel drive up to the claimed 250 km/h top speed.
As long as there’s more than 25% charge remaining in the battery, 0-100 km/h is dispatched in a launch-control-aided 4,37 seconds. Drop below that charge and its back to 170 kW until the batteries have been replenished, either via a plug point (able to charge up to 80% within two hours) or by using the drive systems that include regenerative braking. Here, too, the system decides whether to harvest energy under braking or to decouple the transmission and coast. To maintain maximum charge (and thus performance) while heading out to your favourite stretch of road, a charge-lock function enables the driver to effectively press pause on the electric motor until it’s required. Doing this, of course, nixes the claimed 2,1 litres/100 km average fuel-consumption figure.
Like most hybrids, the best fuel consumption is achieved around town and not on battery-draining motorways. On our fuel route, which incorporates city and freeway driving (see page 108 for a thorough explanation), the i8 achieved a (hugely impressive) 5,3 litres/100 km.
Designed as it is with the passenger cell and 100 kg battery mass centralised in the wheelbase, the i8 boasts close-to-optimal 49:51 front-to-rear mass distribution. Aided by scant ground clearance (117 mm) and a 71 mm rear track advantage over the front footprint – combined with that instant dollop of electrical torque – the i8 is afforded an admirable chance at being a genuine seat-of-the-pants sportscar.
It’s not a chance it seizes, though…
As much as the CAR team admired both its aesthetics and technology, we were not wholly convinced by the i8’s dynamics. Thanks to the standard fitment of adaptive damping, there’s a discernable difference between the firm ride quality offered in sport mode and the softer, more compliant setup in comfort. So far, so good.
However, for the sake of optimal efficiency and aiding the ride quality on poor tarmac, a relatively narrow, tall 195/50 R20 tyre is standard fitment up front. Even with the optional 215/45 R20 rubber fitted to our test vehicle, the i8 will default to gradual understeer long before other vehicles of this persuasion discover their grip limits. It’s also worth noting that the use of lightweight materials functions to offset the additional weight gained by the hybrid technologies. Our test unit weighed in at a portly 1 557 kg.
Test summary
Sound complicated? Well, it is. But it’s worth remembering the i8 exists first and foremost as a showcase of what BMW is capable of in terms of gaining maximum efficiency with minimal sacrifice to performance. Certainly, the end result could have been less complex (imagine the M3’s turbocharged inline-six in this package), but that would have been to the detriment of what the i-brand represents for BMW.
As it stands, there’s a premium price to pay for this type of technology (that said, 90% of owners laid down deposits long before fuel-consumption figures were quoted), but as you can read on page 22, it won’t be much longer before even an entry-level 3 Series boasts similar hybrid systems.
BMW fans shouldn’t feel disappointed that the i8 finishes behind the 911 Carrera 4 GTS and ageing Audi R8 in our Match-up voting. Simply put, as a sportscar in this price bracket, BMW’s first attempt at using hybrid power falls short in terms of outright performance and driver enjoyment. However, as a step towards the inevitable future of fast motoring, BMW should be applauded for getting us very excited.