Over the past few years, more automakers than ever have started to promote something called active shutter grille vents. 

Essentially a way to boost fuel economy at higher speeds, active grill shutters are now being used by GM, Ford, and Chrysler--among others--to give gas mileage boosts to their highest-efficiency models.

But what are active shutter grille vents, and how do they work?

In a conventional, front-engined, water-cooled, gasoline car, air is drawn through the grille and into the engine bay, either sucked in by the radiator fan, or forced in by the movement of the car through the air.

The majority of that air then passes through the fins of the radiator located directly behind the grille, helping cool down the coolant within, which in turn keeps the engine cool. 

Unless that engine is working extremely hard, or is in a hot climate, however, there is often more air entering the engine bay than is needed to keep the engine cool. 

Moreover, that unnecessary air entering the engine bay can add significant aerodynamic drag to the car, increasing the amount of energy needed to move it along and thus decreasing gas mileage. 

The higher the speed, the higher the aerodynamic drag. 

It’s at those higher speeds, when the active shutter comes into play. 

2013 Ford Escape, launched at the Los Angeles Auto Show, Nov 2011

2013 Ford Escape, launched at the Los Angeles Auto Show, Nov 2011

Using a series of small shutters similar to the ones you’d find on certain window blinds--and an electric motor--cars like the Chevrolet Cruze Eco, Ford Focus SFE and Dodge Dart Aero can automatically close part or all of the grille, reducing or stopping the air flow to the engine bay.

The reduction in air flow reduces drag, making the car slip through the air more easily. This, in turn, reduces the amount of energy needed to push the car along, increasing gas mileage. 

If the engine gets too hot, the active shutter system can automatically reopen the grille, ensuring much-needed air can reach the radiator and prevent engine overheating. 

Like engine stop-start and turbocharged engines, active shutter grille vents can help improve your gas mileage by a few mpg over an identical model without them fitted. 

And with more cars than ever, including the 2013 Ford Escape EcoBoost 1.6-liter and even the 2013 Ram 1500, turning to active shutter grille vent technology to save gas, it’s certainly worth checking to see if your next car has this cheap yet effective fuel saving technology fitted. 


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