The 2009 GMC Acadia SLE-1 FWD is the basic model and comes equipped with a 3.6 L V6 engine that can produce 288 hp. This engine comes standard with a six-speed automatic transmission with overdrive. The Environmental Protection Agency has now released their new fuel economy rating guidelines for all the 2009 vehicle models. For this Acadia model, with front-wheel drive (FWD) the fuel economy ratings are 17 miles per gallon in the city and 24 miles per gallon when driving on the highway. These two figures come together for a combined rating of 19 miles per gallon.