General Motors' full-size pickup trucks may be next in line to get thermostatically controlled louvers behind the grille to improve aerodynamics. SRG Global, which produces a variety of components for numerous manufacturers, is developing just such a system for GM's trucks. Similar systems will debut later this year on the Chevrolet Cruze and later on the new Ford Focus.
One of the biggest sources of aerodynamic drag and turbulence comes from the air flowing through a vehicle's engine compartment. Closing off the grille to limit this airflow can drastically reduce this issue, however, the engine still needs air for cooling – especially at lower speeds. At higher speeds, the increased air velocity means less open area is required for adequate cooling.
Thermostatically controlled slats monitor coolant temperatures and then open or close as needed, giving the best of both worlds at the expense of a bit of added cost and complexity. That said, SRG's new designs will integrate the slats into the grille structure reducing the cost of the system and making assembly simpler. Theoretically, such technology could also be used to improve cold-weather warm-ups by keeping the grille's slats closed.
[Source: Ward's Auto World]