The rumour mill has been whirring lately with a lot of speculation as to whether the second-generation BMW i8 will go electric only. We know that BMW will be making some key decisions on the replacement for the i8 before the end of the year and according to Autocar 'sources' within the manufacturer have indicated that an all-electric powertrain is being favoured.

Of course, this sounds a lot like Chinese whispers, but in amongst all of the 'he said, she said' are some tantalising indicators that would seem to back up the theory. There are also plenty of reasons why BMW might decide that hybrid power remains preferable, but let's cover the plus-points first...

The article by Autocar indicates that BMW's Munich-based R&D department is busy beavering away on a high-torque, high-power pure-electric motor with “significantly higher rotational speeds” that mimic the brand's combustion engines' characteristics. Apparently, prototypes of the motor and associated four-wheel-drive system have already been tested successfully in i8 test mules.

This mystery driveline is also said to share much with the one that is being developed for the BMW iNext all-electric SUV, which is already being tested in advance of a planned 2021 launch.

In addition to the powertrain, there is an upswell in the development of EV supercars from the likes of the Tesla Roadster and Audi R8, and a realistic likelihood of Porsche joining the fray once the Taycan has entered production. That's not to say that BMW will be feeling any great pressure to compete, but if it were to, the second-generation i8 is the obvious candidate to take up the mantle.

The major fly in this rumour-flavoured ointment is the fact that BMW doesn't have a platform that suits a pure EV i8. According to the Autocar story, the existing carbon fibre i8 platform “lacks the modularity” required for EV application. This means that the easy option for BMW would be to simply update the current platform and stick with a hybrid powertrain, potentially with a far more potent petrol engine than the current three-cylinder unit.

This would place it below the hybrid hypercars from the likes of McLaren, Porsche and Ferrari, and into a zone that is more the habitat of the Honda NSX (itself an electrically assisted car rather than a PHEV) and... not a lot else, really.

So, where does this leave us?

Well despite questioning BMW's UK PR team on the subject they remained resolutely tight-lipped. The all-electric i8 remains a rumour, but one that – if Autocar's digging is to be believed – is more than a little bit likely to actually come to fruition. We certainly think that this is a golden opportunity for BMW to establish itself in the electric supercar sector long before some of its main rivals will get there.

Second generation i8 has a planned launch of 2023, but with those high-level decisions being made before the end of this year, keep your eyes and ears open for more news on its development.