BMW i8 2015 Review

The flagship of the burgeoning BMW i brand, the i8 two-door sports coupe, makes some big on-paper promises, combining green (fuel consumption of 2.1L/100km and 49g/km CO2 emissions) with mean (outputs of 266kW/570Nm and 0-100km/h in 4.4 seconds) in a shape so exotic it will have Chapel Street cyclists swerving as they reach for their camera phones.

The detail behind these incredible figures is a demonstration of how serious BMW is taking its green-tinged future.

The architecture within the i8, known as LifeDrive, is the first platform to be designed from the ground-up for use in electric vehicles. The ‘Life’ element is made from BMW’s own carbon fibre reinforced plastic (CFRP) and forms the strong, light 2+2 passenger cell structure that is said to be 50 per cent lighter than steel, and the use of a magnesium instrument panel shaves 30 per cent off the unit used in the 6 Series.

All up, the twin-motor, two-gearbox, all-wheel drive, battery-boosted i8 weighs only 1485kg.

Cradling the Life module is the ‘Drive’ element that houses the chassis and drivetrain components, while outside the i8 is clothed in thermoplastic polymers -- again half the weight of sheet steel as well as being better able to withstand minor damage, while being corrosion-free.

The concept car curves are designed with maximum airflow efficiency in mind, contributing to a drag co-efficient of 0.26 Cd, with the scalloped rear pillar section also aiding downforce without resorting to traditional wings and spoilers.

Sitting behind the Life module is a turbocharged 1.5-litre three-cylinder petrol engine, a motor of increasing familiarity to the BMW Group.

In the i8, it produces no less than 170kW at 5800rpm and 320Nm at 370Nm. Coupled to this is a 15kW/50Nm high-voltage starter motor which can also recharge the 7.1kWh (5.1kWh usable) liquid-cooled lithium-ion battery pack, mounted in the traditional transmission tunnel location for a low centre of gravity. Its positioning helps the i8 to a 49/51 front/rear weight distribution.

The petrol engine drives the rear wheels via a six-speed automatic transmission, chosen over the newer eight-speed unit for reasons of packaging and weight saving.

A 96kW/250Nm synchronous electric motor sits up front and drives the front wheels. In electric-only eDrive mode, this can propel the i8 for a maximum range of 37km, and is capable of hitting 120km/h.

Combined with the petrol engine’s 42-litre fuel tank, BMW says the i8 has a range of 600km.

Enough of the techy spec… it’s time for a drive.

On first approach, there’s a sense of theatrical drama to the i8 that rekindles images of the original M1 supercar. Opening the scissor-doors may not excite in the supermarket car park (“The i3 is for the shops,” said one BMW exec), but it sure wows the crowd assembled along the Yarra River, revealing the carbon-fibre of the Life module in the process.

Also theatrical is the traditional supercar access method: bum-onto-sill, drop the left leg in and slide.

Once inside, the i8 continues to wow as only a $300,000 sports car should; with competition including the Audi R8 and Porsche 911 you’d expect nothing less.

The cockpit itself is angled seven degrees towards the driver in the best ‘Ultimate Driving Machine’ tradition, instantly raising expectations, and there’s ample interior room for both front passengers.

Although the back seats offer ISOFIX and traditional child seat anchor points, the reality is it’d be a tight squeeze for anyone beyond young teen size.

BMW has deliberately kept the i8 to four colour options; Blue, Silver, White and Grey, with three interior choices and only three cost options, two of which are equipped in the tested vehicle: Anthracite roofliner ($800), seat belts in BMW i Blue ($800) and the ‘Halo’ interior design ($2500), which uses natural leather extended beyond the seats and includes the first two options in the price. A choice of 20-inch alloy wheels is available for no extra cost.

In default comfort mode the i8 uses a combination of petrol and electric power, shifting almost imperceptibly between pure electric and combined power, the only giveaway being the engaging thrum of a three-pot smoothing into life.

There’s also an Eco Pro mode which optimises powertrain efficiency while minimising energy soak through seat heaters and climate-control functions.

A separate button engages eDrive, the pure EV mode and, given the Melbourne CBD start to our first drive in Australia, it makes sense to give it a try, safe in the knowledge that pedestrians can hear us approaching via the audible ‘drive’ sound which is projected outwards at speeds of up to 30km/h,

Immediately the torque reaction impresses, the i8 far more capable of keeping up with traffic than, say, a Prius.

This mode will take near full throttle, the petrol engine only engaging if the ‘kickdown’ false throttle stop position is breached. Even at highway speeds, the eDrive mode proves more than capable, though it does swallow range when driven in this manner.

Indeed, heavy-footed driving can wipe the pure EV range away almost as quickly as one counts down to take-off. It’s just as well that in sport mode, the i8 is a rocketship.

Sport is accessed simply by nudging the floor-mounted gearshift to the left. Suddenly the dash display glows red with a tachometer where previously green info was displayed and the i8 tenses, the steering sharpening and the (standard) electronic damping firming things up a couple of notches.

The second electric gear is also imperceptibly engaged to alter the torque transfer rate and increase the top speed, according to BMW. The result makes the i8 a very different proposition, one capable of accelerating from 80 to 120km/h in an amazing 2.6 seconds -- faster than the M4.

It’s not only in acceleration that the spaceship link works, for the combination of ‘natural’ three-cylinder warble is amplified through the stereo system in a similar vein to the M5 (and others).

The result, especially when interlaced with the electric motor whine, is digital, synthesized and the kind of sound movie-makers use when an alien craft looms into view. Even the gearchange ‘pops’ are falsified. In honesty, I’d rather just hear the characterful motor sans embellishment.

On a section of bumpy road, the i8’s stiffness in sport mode can be felt with a slight jiggling sensation through the chassis, but it quickly resets. The steering, though light at any speed, is actually very accurate, allowing you to point the front-end confidently at the apex.

Back on the power, there’s an initial scrabble as the relatively narrow 215/45 R20 Bridgestone Potenzas (245/40 R20s at the rear) squeal in protest as they take on the instantaneous electric torque, before the i8 balances out beautifully to slingshot towards the next straight.

It’s extremely impressive, but to make the most of Australian roads a capability to run the dampers in comfort with the powertrain and steering in sport mode would be ideal.

Driven hard in sport mode, the i8 managed a 10.2L/100km average; probably still ahead of a similarly-driven 911. Make of that what you will…

After spending time with the i8, it appears enthusiastic drivers are safe – the i8 can play hard as well as green. BMW has once more been an early adopter and answered the ‘Can hybrids be fun?’ question. Emphatically.

Also consider: Audi R8, Mercedes AMG GT, Porsche 911