Fuel-Efficient Four-Cylinder Engine Key To 2016 Ford Mustang Sales Success

Last year, a new generation of Ford Mustang launched, featuring the model's first four-cylinder engine since 1993.

And for that car's first model year so far, it's looking like a major contributor to the Mustang's sales success.

The 2016 Mustang is currently the best-selling muscle car, and the EcoBoost engine reportedly accounts for a significant number of those sales.

DON'T MISS: 2015 Ford Mustang Gas Mileage: EPA Ratings For All Models Released (Sep 2014)

The EcoBoost's attractiveness to younger buyers is helping the Mustang pull ahead in the sales race, reports The Detroit News.

Mustang sales were up 55 percent in the first five months of 2015, compared to the same period last year.

Between January and May, Ford sold 56,571 Mustangs according to Autodata Corp., handily beating its rivals.

General Motors sold 33,982 Chevrolet Camaros during the same period, while Fiat Chrysler Automobiles sold 30,166 Dodge Challengers.

Both the Camaro and Challenger are only offered with V-6 and V-8 engines at the moment.

While the muscular V-8 gets most of the attention, Mustang sales may actually be dependent on the less-expensive four-cylinder engine--which more people are likely to buy.

Millennial buyers are thought to prefer the EcoBoost engine for its fuel economy, and they're now a larger share of Mustang buyers.

ALSO SEE: 2015 Ford Mustang Revealed, With First 4-Cylinder Since 1993 (Photos) (Dec 2013)