According to international reports, the new sedan will slot in between the upcoming BMW i3 and the sporty BMW i8 (both set to launch in 2013), as a large luxury eco-friendly sedan. On the other hand, these images could prove BMW is simply testing new underpinnings that could be adopted by various BMW models in the future.
Specific details of the prototype are hard to come by, but if you take a look at the images closely, particularly the front wheels, you'll see a set of electric wheel hub motors. The rear doesn't feature the same setup, pointing to a potential front-wheel-drive-only electric drivetrain. The prototype also features a rather narrow wheel and tyre package, reducing rolling resistance.
Other subtle revisions on this prototype over the normal BMW 7 Series include new front and rear guards, highly noticeable at the front where the wheel arch almost extends up to the bonnet line. This hints further that there are some fairly vast changes going on underneath.
It's possible the car could feature a range-extending hybrid powertrain, relying predominately on electric power, or a fully electric layout. We'll be sure to keep you updated on more concrete details when we hear more.