You're probably well aware of the U.S. government's motive to enforce higher fuel-economy limits. The solution for some automakers, is as simple as compromising a bit of power. Built given BMW's legacy of speed, courage, and superior handling, "less" and "powerful" are two ideas that do not coexist in the minds of the Bavarian automaker.

As such, in deciding to retire the V10 engine, which powered the last-gen M5 in an effort to make the speed-demon more efficient, they'll also be making the super sport sedan more tenacious.

BMW improved the fuel economy, power and torque of the new M5 by replacing the V10 with a twin-turbocharged V8. The company indicates that the new twin-turbocharged V8 engine is approximately 10 percent more powerful than the V10 it replaces. Plus, it delivers up to 30-percent better fuel efficiency!

Happily, drivers don't have long to wait before enjoying the power gains for themselves. The new, fifth-generation BMW M5 is expected to arrive at dealerships in 2012.