The drop-top hybrid roadster
When we assembled in sunny Mallorca to drive the new BMW i8 Roadster, essentially the sci-fi i8 with its roof lopped off, I had only one pertinent question to ask, from an auto-geek perspective: with the roof off how had the structural integrity been addressed? Had it been beefed up and if so how much was the weight penalty, more so because BMW’s pioneering mass-produced carbon-fibre tech would have needed even more ingenuity for such an application.
The answer from the BMW boffins stumped me! “No we haven’t done much on this issue and in fact the superstructure’s overall structural rigidity might have slightly reduced,” said Rainer Rump, project head for the i8 Roadster. And before I could pop in another question given the look of incredulity on my face he added, “We have however addressed this with more tweaks to the suspension and the rubber used and the car performs just as well. Hope you will experience this for yourself the next day on the twisty mountain roads and we will discuss it later the next evening over dinner.”
Structural integrity of the BMW i8 Roadster
This was stunning to say the least because it’s a rule of thumb that cabrios crafted out of coupes and GTs invariably have added structural members wrought into the monocoque so that the sporty ride and handling aren’t compromised by flex. The overall robust nature of the design of the i8’s carbonfibre tub cum bodywork however allows the i8 Roadster to perform just as well as the Coupe! Also as I found out, I thought it brings in a whole new experience to what was earlier gimmicky and more Star Wars than a new leap in the forefront of changing automotive technology.
When I had first driven the i8 about three years ago in Italy, I had found that it was more in the realm of getting on to the social aspect of making sportscars more tolerable to the green brigade (who might never have got into sports cars anyway!). With its roof now lopped off but with those dramatic butterfly doors yet retained, the original sci-fi character of the car has been transformed more into a supercar stance and look and that’s most welcome. However in case you are considering this to be the equivalent or an alternative to the likes of the established Porsche 911 or the Audi R8, you need not apply here.
What you could look forward to however from the i8 Roadster is a more involving and better driving GT-esque machine that is capable of pulling in smiles even before you know it! For starters, the car handles impeccably and this has all to do with more feel engineered not just into the revised steering set-up but also in the way the braking system has been recalibrated for mere mortals. Let me explain. One of the early grouses in the i8 came from the wooden feel from the brake pedal when the anchors were thrown in and also the vague floaty steering that seemed lifeless in informing its pilot what it was doing. The ride and handling boffins at BMW, aided by its phalanx of DTM race drivers on contract performed the overall tuning of the suspension, steering and brakes while keeping in mind the rigidity of the monocoque. I won’t get into the details of what and how long it took to achieve a major improvement to delight whosoever gets to pilot the Roadster but the result is more feel and feedback from the steering, including being nicely weighted and this allows one to thrown the car into tight as well as fast corners and come out grinning stupidly! All this is heightened further in Sport mode and what you get is one strong surge of performance with the manners to match.
120kmph in pure electric propulsion and a range of 53km
Speaking of performance (yes I will get to the brakes after this because it is a performance issue!), the basic 1.5-litre triple is retained almost in the same trim and spec as in the i8 from day one but a new battery pack has been added (cell capacity upped from 20 to 34Ah), without any gain in weight. This effectively means that overall power has increased to a total of 374bhp with the petrol motor accounting for 231 horses (made at 5800rpm) and the new high-density batteries cum motor delivering 143bhp (at 4800rpm). This is a near 12bhp increase from the electric propulsion system but what is even more useful is that it helps boost the i8 Roadster’s pure electric drive in hybrid mode to 105km/h which could be further upped to 120kmph in activated eDrive mode if you are for spirited motoring! Of course, the i8 Roadster has an all-electric range of 53km. The six-speed Steptronic transmission is retained for the petrol only and hybrid modes while a two-speed automatic gearbox handles the electric drive to the front wheels.
Naught to 100kmph in 4.6 seconds with a top whack of 250kmph
And here is where we need to speak about the brakes for a car that can zap from standstill to 100kmph in just 4.6 seconds (no slouch this for a car that not many consider a supercar rival to the established mandarins in class) and run up to an electronically limited 250kmph max speed. The brakes feel more progressive as well as seamless, thanks to the change wrought from switching over from just energy recuperation to a more conventional braking feel and that helps quite a lot. In the course of my drive around the island, I discovered enough new facets of this car that I am sure only build up its armoury of delights. The State-of-Charge mode helps to idle around in quiet splendour while yet maintaining a healthy level of battery juice, this being so very important when I was under attack from cyclists both from the front and also those who I had to overtake! Mallorca is a haven for bicycle sport in Europe and with a big fixture lined up for the coming weekend, it seemed that all the world’s bicycle racers had congregated here to just spice things up! And yes one more thing, if you seem to have run out of charge the best way to get them all tanked up was to select Sport mode enabling the three-cylinder engine to top up the battery on the move!
“The BMW i8 Roadster delights and delights comprehensively, more in the way of fine manners, good feedback and fantastic looks and creature comforts making it a great all-day driving tool”
A crowd puller
So far so good but the i8 Roadster is now a magnet, which could be handful on narrow roads teeming with cyclists as I found out. For one it is way too wide and given its silent electric operating nature, creeps up on vehicles ahead rather surreptitiously! BMW had thought this thing through and the new i8 Roadster has its engine note multiplied by an equaliser-based sound system, which via a loudspeaker housed in the left underside of the car and pointing down delivers a slightly roarty audio!
That aside this is a car, which delights and delights comprehensively, more in the way of fine manners, good feedback and fantastic looks and creature comforts making it a great all-day driving tool. The top folds down completely and nestles into a very tiny space without impeding the luggage space (good for a couple of overnighters!). It might not find favour with the sportier set but on its own in a class of one – still the world’s best selling petrol-electric hybrid sportscar – it is now a more involving automobile to drive fast without harming the environment. And yes it also stays steadfast to doing more from less and in this no one comes close, as yet!