Fully electric i8 not yet viable: BMW

A FULLY electric version of the BMW i8 will not be offered anytime soon, despite forthcoming models from the car-maker’s i Division such as the forthcoming iX3 SUV and i4 mid-size liftback moving to battery power only.

In the four years since its release, the petrol-electric hybrid i8 has been bombarded with faster competition from both internal combustion engine-equipped (ICE) rivals and electric vehicles (EVs) such as Tesla’s Model S.

The just-launched facelifted i8 continues to use a 1.5-litre turbocharged three-cylinder and electric motor combination, with the $300K-plus hybrid delivering a 4.4-second 0-100km/h claim.

While a circa-$235K four-door Model S claims a 2.7s 0-100km/h using battery power alone, BMW i powertrain sub-project manager Ingo Tassinger insisted that a sportscar demanded low kerb weights and a long driving range – two issues that still plague heavy battery packs feeding powerful electric motors.

“It (Tesla performance) is a figure that you have there but I think it’s also about how dynamic does the car feel,” Mr Tassinger told GoAuto at the international media launch of the BMW i8 Roadster in Majorca, Spain, last week.

“For sure you can have very good figures on (straight line) performance but you also have to handle the car, you go through curves and I think that makes the balance you want with weight and with power.

“I think battery development is still an issue and it will improve over the next years, but sure. (But) I think with the i8 Roadster you want to take a nice scenic route and you will certainly need a certain range with the car, and with a certain range you would also need to have, when you go for a pure electric car, a battery of a big size which also means weight.

“We have projects that focus really on this pure electric in the i4 and i3. But I think this does not mean that all cars need to be pure electric. So for us the hybrid system is still a valid option in terms of … the power to weight.”

BMW i media relations manager Paloma Brunkhorst further clarified that, “700 kilograms (of batteries) in a sportscar, right now it doesn’t make sense.

“If you put a big, big, big battery in there it is not that fun driving like it is today. So you always have to look at range, weight, driving dynamics, they always have to fit (and) I think the plug-in hybrid technology is not a technology which will end in a few years, I think it will go further.”

Where the i8 Coupe weighs 1535kg and is very close to that of a BMW 330i sedan, for example, a dimensionally larger Tesla Model S P100D weighs 2241kg.

However, while BMW i8 project manager Markus Plunkte confirmed that BMW had decided it would permanently offer an electrified sportscar in its range, he too reiterated that the weight of batteries was going to continue to be an issue.

“What I can promise you (is) there will always be an electrified sportscar by BMW,” he told GoAuto at the i8 Roadster launch.

“If it will be an i8, or it will be another car, we will see how quick technology evolves and what the market with the customer demand will be. We will see. We will check all the options and then see what will be the best.

“I think the battery technology one day could be good to do a really proper sportscar. But as for a sportscar it’s more than 0-100km/h acceleration, but it's really about cornering, and that is where the i8 really is brilliant. So it’s about weight, weight distribution, and the very stiff body.

“So you do not want to put an 800-to-900 kilogram battery pack into a sportscar to get the power. And we don’t want a sportscar that would be like limited to where the customer lives and maybe just to take it out of the garage, show it off a little and then bring it back. We do a sportscar that needs to be a proper usable sportscar as the i8 is.”

Although today a circa-500km total driving range required a heavy battery pack, Mr Plunkte conceded that “battery technology is evolving fast”.

“I mean, if we look at the i3 we started in 2013 and with the battery update, (we have seen) already a plus-50 per cent increase in only a couple of years, and of course these developments go on and on.

“So I’m confident that there will be a day when you can do a pure electric sportscar with enough range, with enough power and without having exceeded a two-tonne weight overall. We will see when this technology moves to that point.”