Test Review: BMW i8 roadster (2018) isn’t built for tunnels

BMW has doubled the model line-up of its i8 with the addition of the i8 roadster. ‘Hooray’, we hear you shout followed in a softer tone by the question ‘didn’t BMW attempt such a thing in 2012?’ Yes, the six-year wait has come full circle, peppered along the way by versions such as the futuristic i Vision Future shown at the 2016 Consumer Electronics Show. In our hearts and minds, the i8 has found that missing piece. It’s now as complete as we can fathom.

We must remind ourselves that the i8 is the vanguard of hybrid performance and desirability. Confronted by coupe and roadster on the international drive, I can attest that the feeling has, if anything, grown. I mean just feast your eyes on the images. BMW hasn’t tinkered with the basic proportions but now, bowing to popular demand, the company has introduced a roadster version to scoop up any temptation that might see customers head over to a 911 convertible, Mercedes-AMG GTC roadster, or Audi R8 Spyder. In the sportscar segment nearly everyone is expanding with a roadster alternative so this is BMW ticking another box – believing it will double profits.

So why did the BMW i8 roadster only come to fruition now? Development of a coupe and roadster usually occur in parallel to maximise R&D but BMW never intended the i8 to be anything other than a coupe. The complexity is far greater than it looks; new seats had to be designed to pass crash tests and airflow management from the bonnet vent had to be redirected because engineers found that hot air was tumbling over the windscreen and into the cabin. So it renders the bonnet vent a superfluous element (on coupe too) but we’re talking hybrid here, aren’t big vents and ducts passé?

Engineers, stylists and bean counters should be lauded for the little compromise between i8 coupe and i8 roadster. The i8 roadster hasn’t vetoed those gullwing doors. That’s the sort of hinge-witchcraft you get with a McLaren 570S Spider. Around the back, the differences are pronounced yet it’s the sort of taut, flat styling that justifies BMW’s choice to use a lighter fabric roof which it manipulates into a room that still permits a small but deep boot.

That and the fact that the i8 roadster comes with storage space in lieu of the coupe’s rear seats give some flexibility, but lockable, safe storage is an issue.

Carefully lower yourself by supporting your weight with your one arm outstretched to the door and the other poised to soften the crash (while vaulting the high wide sills) and drop into a cockpit guided by the familiar menus and buttons. iDrive system, a small touch-enabled screen in the centre, TFT dials, and new head-up display, all plug in seamlessly with our sixth sense.

The new BWM i8 roadster adds noise cancelling which uses little microphones to record interior noise. The system then inverts the polarity and plays it back through the speakers. The result? A suppressed supercar growl but a pleasant conversational GT cruiser. Such is the design and attention to detail that new fabric covers for the speaker grilles stop wind from swirling around in the old ones.

Ok so the i Vision Future Spyder with its Air Touch interface that shunned all buttons is sadly not replicated in any shape or form (concept frustration) – BMW could use the i8 to start its next chapter of interior experience because it’s not quite as revolutionary as the rest of the car.

Battery tech has come a long way since the launch of i8 and i3 so it’s a matter of replacing the old with the new. This is possible because although the new batteries yield higher efficiency, the physical dimensions haven’t changed. Mind you, it’s still hard to get excited by the alchemy of battery tech; does a cell capacity of 34 Ah (from 20-) and gross energy capacity up from 7.1 to 11.6 kWh gird your loins for the future of speed? Either way, the important relatable number is 105kW of electric power which is up by 9kW. Hardly the development progress leap we were expecting – you usually see bigger gains from each evolution of the internal combustion engine. Except in this case because the 170kW, 320Nm 1.5-litre 3 cylinder is unchanged. Pity.

Hybrid cars are all about the numbers. What appear to be dry insignificant gains on a chemistry paper blossom into big improvements in emissions free driving. Speeds up to 120km/h (previously 70kph) in EV mode with an electric range of just over 50 kilometres which sees the new i8 around 10km further up the road compared to what came before it. But for me it’s the performance numbers that disappoint a fraction – the bite isn’t bigger than the bark.

A 0-100km/h of 4.4 for the coupe is no faster than before. If you opt for the heavier roadster, it fares worse in every measurable test from range, C02 and acceleration. The marriage between hybrids and roadsters is flawed on multiple levels compared to its coupe sibling because weight is the enemy of any hybrid. It’s a philosophical conflict.

Accepting that this BMW i8 roadster is not going to echoe off the walls of a long tunnel, the 1.5-litre musters a sunny warble when in Sport Mode. A BMW M240i coupe makes the hairs on your neck stand up a little faster – in fact anything from the M catalogue thrills a little harder. The i8 has to be the proverbial jack of all trades. And the pioneer of many new ones.

But those are driver’s cars. The i8 roadster is a geeky car for the tech-savvy which also happens to be quick. There’s nothing else that comes remotely close to possessing the same bandwidth. The i8 remains a benchmark marriage of speed and efficiency, drawing the roadmap for others to follow. In fact, the i8 inspires bright minds. The modern poster car.  I feel proud to be at the wheel in the year 2018 but I do wish BMW had poured equal amounts of R&D into its combustion engine as it has done with the EV side of things.

So we arrive at a crossroads which is a neat metaphor for the i8 in general. Remarkable that given how quick brands are to close gaps that the i8 has existed in this segment almost completely unchallenged for the last four years. The next six months will change all that with a swell of newcomers but BMW’s holding the lead and within a growing i-brand, both the i8 coupe and i8 roadster remain at the apex. Andrew Leopold

SPECIFICATION

• R2 329 300
• 1499cc 3cyl, turbo petrol, AWD, 275kW, 570Nm
• 2.0l/100km, 46g/km
• 0-100km/h in 4.6secs, 250km/h
• 1595kg
• Verdict: Multiple personalities see it almost equal in its sportscar and EV balance. Heavier roadster undoes some of hybrid’s progress and petrol engine could do with more fizz.