The 2015 Ford Mustang has a tricky job to do. Not only must it impress fans of previous Mustangs, but as sales expand into Europe it must become more efficient too.

To that end Ford has installed a four-cylinder engine for the first time in many years, but it's also worked on aerodynamics--such as active grille shutters.

When it arrives, the 2.3-liter EcoBoost model will play a middle ground between the thumping V-8 and entry-level V-6 models.

But for customers wanting high performance with reasonable efficiency, it's sure to be the pick of the range--particularly for customers in markets where fuel economy and low greenhouse gas emissions are vital.

According to The Detroit News, Ford has spent twice as long perfecting the aerodynamics of the new Mustang than it did the last version, both using computer modeling and real-world testing in the wind tunnel.

While the engine itself will do the most for the new Mustang's economy, the aerodynamic tweaks amount to a three percent improvement, for a one percent boost in highway fuel efficiency.

Active grille shutters on the EcoBoost actually serve two purposes.

The turbocharged engine needs more cooling air than atmospheric engines, so Ford has opened up greater space behind the grille to allow this air to filter through.

The problem is a large grille like the Mustang's can act as a bit of a parachute, harming the car's aerodynamics.

When cooling demands are lower, shutters behind the grille can close, preventing as much turbulent air entering the engine, therefore reducing drag. It's a system seen before on Ford's current Focus and the larger F-150.

Ford has also utilized front wheel "aero curtains", that draw air through the front of the car and direct it around the front wheels--forcing air flowing around the car away from the wheels where it can create turbulence.

The mirrors have been moved too, relocated from the front pillar to the door--said to eliminate a vortex-like swirl of wind that beats against the windows (and can cause an uncomfortable thrumming with the windows down, too).

It may not turn the Mustang into a Prius-beater, but it'll certainly help the car compete in markets where fuel economy is as important as a car's performance.


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