The BMW i8 is a new age sports car, but it proves that the basic tenets of involving handling, strong straight-line performance and eye-catching styling will always be central to the sports car proposition.
With its clever hybrid drivetrain, the i8 is very nearly as accelerative as a Porsche 911 Carrera, but it can also cover close to 32 kilometres in electric only mode, which makes it a unique offering at this price point. The drivetrain is certainly an impressive technological achievement and an object lesson in systems integration, but it lacks the emotional appeal of a soulful, high-revving engine and that will count against it among certain traditional sports car buyers.
Aside from slightly remote steering and a lack of outright grip across the front axle in hard cornering – a result of its narrow tyres – the i8 is genuinely fun to drive. It has superb body control and excellent balance.
Performance and 0-100 time
The i8’s performance is quite frankly astonishing for a car with a three-cylinder engine. The combination of a 170kW petrol engine and a 96kW electric motor means it can deliver an M3-rivalling 0-100 km/h time of 4.4 seconds.
The combined hybrid system also generates 569Nm of torque with the electric motor generating the entirety of its shove immediately. That means that the i8 actually ends up feeling a bit quicker than it reads on paper.
What’s most impressive with the performance of the i8 is how the two systems work together to create a very clever four-wheel drive setup. The electric motor drives the front axle, while the petrol drives the rear. They both fill in for each other, with the electric motor providing power at the lower end of the rev range and the turbo three-cylinder unit filling in at the top.
This distribution of the drivetrain also helps translate to a perfect 50/50 weight distribution. As for the i8’s weight itself, the car manages 1485kg despite its 7.1 kWh lithium-ion battery. This is thanks to its clever hybrid carbon-fibre/aluminium structure, which saves weight, keeps occupants safe and is nowhere near as expensive as a full carbon-fibre tub.
BMW’s TwinPower 1.5-litre three-cylinder delivers a soundtrack that does the i8’s looks justice. Obviously a large part of that comes from cleverly synthesised audio work, but in a car as ‘digital first’ as the i8, it’s more forgivable than in the likes of the M3 and M4. Just don’t open the windows in a tunnel and expect your ears to be blown off, as a lot of the noise the i8 makes is a cabin-only affair.
Engine and gearbox
While BMW won’t thank us for saying so, the three-cylinder TwinPower 1.5-litre engine in the i8 is essentially a heavily reworked version of the unit found in the base-model Mini Cooper.
We say reworked, because it generates 170kW and 319Nm of torque. This is then combined with an electric motor on the front axle, which produces 96kW and 250Nm.
As if the powertrain wasn’t complicated enough, 8kW of hybrid drivetrain is generated by the starter motor, which also serves to torque-fill where the petrol engine is still spooling up its turbo.
The complicated drivetrain demanded an equally ingenious transmission. Essentially, power from the petrol engine is transferred to the rear-wheels using a six-speed auto and the front handles the electric motor using a two-stage automatic box. The driver controls the six-speed either by leaving it in auto mode or via the shift paddles on the steering wheel.
In Eco mode, the gearbox does as you’d expect, shifting up at just the right moment to achieve maximum efficiency. Switch to Sport however and it’ll hold gears a lot longer. Shifts aren’t double-clutch gearbox quick, but they’re more than fast enough.
Ride and Handling
BMW makes a great deal of noise about the i8’s ecological credentials, so it almost comes as a surprise to learn that it’s genuinely fun and engaging to drive quickly. It has better body control over a cresting, undulating road than any of BMW’s high performance M cars and it feels agile, darty and poised in corners. The hybrid drivetrain also gives it serious straight line performance – enough to keep up with a Porsche 911 Carrera S until 160km/h.
Its dynamic weaknesses are the steering, which feels remote and lifeless, and the ultimate lack of grip across the front axle. You’d need to be pushing hard on the road to provoke that understeer, but it’s very prominent on the circuit. Both of those things mean that the i8 falls a little way short of conventional rivals such as the Porsche 911 and Mercedes-AMG GT for outright thrills – but it is better to drive than we imagined it would be.
That being said, we do have issues with the brake pedal feel. The i8 uses regenerative braking to help recharge the batteries. This means that the car switches between its two brake systems during a braking manoeuvre, which gives an inconsistent pedal feel.
In everyday driving, the i8 is refined, it rides comfortably for a car of such performance and there are no histrionics from the complex drivetrain around town. When in electric-only mode it has enough straight-line performance to dismiss most traffic away from the lights, all without making anything more than a distant hum. HUNTER SKIPWORTH
‘The i8’s batteries are located low in the chassis and within the wheelbase, which gives it perfect natural balance. It also has better body control over a tricky road than any of BMW’s high-performance M cars. In fact, there is so much untapped potential here that an M version would surely be something very special indeed.
‘As it is, the i8 is let down slightly by its vague steering and low rolling resistance tyres, but that’s only in extreme cornering. For the most part the i8 is a very convincing machine that augers well for the future of the sports car.’ Dan Prosser, road test editor