Sometimes, making cars more efficient is best done through the application of more fundamental principles such as improved aerodynamics, rather than complex and expensive powertrain upgrades. Mercedes Benz is embracing that philosophy, with a plan to bring the respective drag coefficients of its cars below 0.20Cd within the next five years.

The carmaker claims it already produces the world's most aerodynamic production car - the new 2010 E-Class Coupe, which scores a drag coefficient figure of 0.24Cd. The new coupe even manages to out-slip the new 2010 Toyota Prius, which for a short time in January could claim it was the world's most aerodynamic production car along with the Honda Insight at 0.25Cd.

However, despite the E-Class Coupe already posting impressive aerodynamic credentials, Mercedes is keen to improve in this area. Speaking with Autocar, E-Class Coupe project manager Rainer Tiefenbacher revealed that there was “still plenty more to come” in terms of improving fuel efficiency.

“There are big steps to be made, especially around and under the engine hood. Twenty years ago we celebrated a 0.30Cd, in five years we will reach the next big step,” Tiefenbacher explained.

Mercedes is correct in that area - the current shape of most cars and trucks make them relatively poor aerodynamic performers. But while carmakers continue to extract as much efficiency out of their cars, we hope aesthetics don't get laid completely by the wayside.