Twin turbo I6 engine and a water-to-air intercooler on new M3







Just the Facts: •BMW is testing the new M3 with a twin-turbo inline-6.
•This prototype features a water-to-air intercooler.
•The new engine is predicted to produce more than 400 horsepower.


SANTA MONICA, California — Every so often, prototype drivers and vehicle engineers have to open the hood, and when they do, spy photographers pounce. Especially when the hood being opened is that of the 2014 BMW M3.

It has been known for quite some time that the 2014 BMW M3 would not carry on the current car's naturally aspirated 4.0-liter V8. Instead, BMW had to come up with something smaller and more efficient. And that likely meant forced induction.

Rumors have been swirling about what form that engine would take: Turbo V6? Turbo inline-6? Supercharged V6? Each rumor had its own reasoning behind it, but the most talked-about prediction was a straight-6 with three turbochargers providing the boost. It sounded exotic at first, but then BMW unleased its 3.0-liter triple turbodiesel in the 550d.

But now we have actual photos of the M3, and the engine bay tells a different story. We're not 100 percent certain, but it looks like this engine has a twin-turbo setup, mostly likely feeding BMW's 3.0-liter inline-6.

Our in-house turbo expert also notes that this setup appears to have a water-to-air intercooler similar to BMW's larger-displacement twin-turbo V8s. The current N55 turbo I6 uses an air-to-air intercooler.

The addition of an extra turbocharger should give this six enough punch to go well over the 400-horsepower mark.

Spy Photos: 2014 BMW M3 Twin-Turbo I6