2016 GMC Acadia is the newer version with some differences, such as the model year, starting price, horsepower, and fuel economy.. First of all, there is a $3,510 difference in the base MSRP. The 2014 GMC Acadia, an older vehicle by two model years, has a higher starting price than the 2016 GMC Acadia. And finally, a bigger engine usually means less mpg. But the 2014 Acadia has a more powerful engine and it gets 1 more mpg than the 2016 Acadia. Among similarities are the body structure, ground shadow size, height, and maximum occupancy.