The 2012 Z4 has a surprise under the hood

This replacement provides the equivalent or better than the existing 6-cylinder in performance, refinement and smoothness with two less cylinders. With 240HP and 260lb-ft of torque, it delivers more power and more torque than the Z4 sDrive30i it plans to replace.

The new BMW Z4 sDrive28i Roadster will be the first model in the U.S. to feature the company's new powerful, efficient and clean TwinPower Turbo 4-cylinder engine. It also marks the return of BMW 4 cylinder power to the United States for the first time in over a decade" , says a BMW engineer.

In addition to the superior power, the 2012 BMW Z4 is smaller and lighter. The manual gearbox weighs 33 pounds less than the inline-6, and the automatic gets about 44 pounds trimmed.

Controversy is nothing new to BMW, they have often taken the road less traveled in both design and performance. The original iDrive did not initially get a warm reception, but it is now available across the lineup. The turbo-charged 1 Series with an M Badge seemed blasphemous, but it turned out to be a fantastic ride. So, this is just par for the course. BMW is mixing it up again by replacing some of its models with a fantastic 4-cylinder engine - a legend in the making that goes by the name "N20".

It makes sense from a variety of perspectives, but none more than efficiency. It is also an enthusiast's dream. So, when we start seeing it in the 5 Series, the X3 and the beloved 3 Series, we'll expect only a few will miss the inline 6 it is going to replace.