File this one in the "highly speculative" category for now, but also in the "highly tempting" sub-folder. For those familiar with the absolutely stunning performance of the BMW X5 M and X6 M, the idea of a smaller, lighter, triple-turbocharged X3 M is breathtakingly cool.
Yes, that was three turbos mentioned. As crazy as it may sound, that's the rumor flowing out of the U.K. via CAR today. The three turbos will be piped into a massaged version of BMW's familiar straight-six--likely meaning a 3.2-liter displacement--and will generate a claimed 449 horsepower.
So how would the three-turbo setup work? With one electric turbo and a pair of the usual type. Electric forced-induction setups are typically used to supply low levels of boost pressure at idle and very low rpms, because it can be driven independently of engine speed or exhaust flow. While it's not explained in the source article, the most likely use would be to provide a baseline level of boost with minimal parasitic losses, thereby allowing larger primary turbos to be used without the accompanying turbo lag that would otherwise be present.
Even more interestingly, the same engine is tipped to power the next-gen M3. The power figures line up surprisingly well with previous reports, though the idea of three turbos appears to be new to the mix.
Like we said, highly speculative, but at the same time, very interesting. Let us know what you think about all this below.