When it comes to fuel economy, the powertrain is the first thing people think of when it comes time to improving it. After that it’s typically vehicle weight. However, one of the simplest and most effective ways of improving fuel economy is through aerodynamics.

Everyone knows that the slipperier a vehicle--denoted by Coefficient of Drag (Cd)--the better the fuel economy. But how does an automaker improve the Cd without significantly changing a vehicle’s size or shape? One way is through the use of active aerodynamics.

GM is one such automaker looking to improve the fuel economy of its vehicles with active aerodynamics, in its case through the use of louvered grilles. Together with plastics specialists SRG Global Inc., GM is developing a new louvered grille designed for its pickup truck range and eventually its entire vehicle lineup.

The louvered grilles will be hooked up to the vehicle’s ECU, opening and closing depending on parameters such as engine temperature and speed. Closing the vents allows the engines to heat up quicker on initial starts and reduces drag, helping to reduce fuel consumption and improve economy.

GM is not alone in its quest for improved fuel economy through the use of louvered grilles--BMW already uses such a system on several of its models, although the special louvers sit behind the regular grille on the German luxury cars.

Watch this space.

[Ward’s Auto]