The redesigned crossover is expected to be unveiled later this year or early next year.
The GMC Terrain was introduced nearly seven years ago so it comes as little surprise the company has begun testing the next-generation model.
Spied at the Milford Proving Grounds, the 2018 Terrain is heavily camouflaged but looks notably sleeker than its predecessor. Styling details are hard to make out but the crossover has a prominent grille, an upward sweeping beltline, and a tailgate-mounted spoiler. The Terrain is also expected to be smaller than its predecessor to make room for the 2017 Acadia which is 7.2 inches shorter than the previous-generation model.
Engine options remain unconfirmed but the Terrain is expected to be offered with either a turbocharged 1.5-liter four-cylinder engine that produces 160 horsepower and 184 pound-feet of torque or a naturally- aspirated 2.5-liter four-cylinder engine with 197 hp and 192 lb-ft of torque. The engine will likely be connected to a six-speed automatic transmission which can be paired to an optional all-wheel drive system.
The 2018 GMC Terrain is expected to be unveiled at either the 2015 Los Angeles Auto Show or the 2016 North American International Auto Show. Regardless of where it debuts, the model is expected to go on sale next summer.