Families in the O'Fallon area looking for a midsize SUV with plenty of utility features should take a look at the GMC Acadia. This versatile vehicle comes in three trims - the rugged AT4, the luxurious Denali, and the stylish Elevation. No matter which Acadia you choose, you'll get a 2.5-liter turbocharged four-cylinder engine making 328 horsepower paired with a smooth-shifting 8-speed automatic transmission.