BMW officially unveiled its i3 concept ahead of the car's on-stage debut at the 2011 Frankfurt Motor Show. Details on the i3 and upcoming i8 poured out. Click here for all of that initial info.
Recently, Consumer Reports' Eric Evarts spoke about the i3 with BMW chief engineer Ulli Kranz. Evarts asked of the i3's optional range-extending engine and, even though Kranz wouldn't discuss specifics, Evarts seems to have prodded Kranz in such a way that BMW's range-extending solution was revealed.
Evarts suggested to Kranz that one of BMW's motorcycle engines would be ideally suited for range-extending duties and, rather than deny this, Kranz' "eyes lit up when it was suggested that a motorcycle engine might be a perfect fit for such a car," according to Evarts.
Furthermore, Green Car Reports speculates that handling the i3's range-extending duties will be one of BMW's motorcycle engines, perhaps the company's twin-cylinder 600-cc unit. Specific details are, unsurprisingly, not available, but that's what future posts are for.