DETROIT – GM’s Cadillac brand detailed some of the specific features on its new 2013-MY ATS that contribute to the sport sedan’s recently announced EPA fuel economy ratings of 21 city and 31 highway mpg for its 2.0L turbocharged engine.

Cadillac offers three engine choices for the ATS: the aforementioned 2.0L, the standard 2.5L four-cylinder engine, which produces 202 horsepower and offers an EPA rated 22 city and 33 highway mpg, and a 3.6L V-6, which can produce 321 horsepower offers an EPA tested 19 city and 28 highway mpg.

Contributing to fuel economy performance is the aerodynamic styling and active aero grille shutters that close when additional engine cooling isn’t necessary. The vehicle also features underbody aero shields that help redirect wind around and under the car (and helps reduce cabin noise). The ATS achieves a coefficient drag of .299, according to GM.

The ATS has a curb weight of 3,315 lbs. and is the lightest luxury sport sedan in the world, GM stated. The Cadillac ATS uses new types of materials in many locations, including ultra-high strength steels throughout the car; an aluminum hood and magnesium engine mounts; a lightweight laminated windshield; and door trim panels made from natural fibers are lighter than the standard-issue plastics.