Two Sedans with more similarities, such as the body structure, market segment, starting price, ground shadow size, height, and maximum occupancy, than differences, like the market segment, horsepower, and fuel economy. First of all, the 2016 Buick LaCrosse has bigger and thirstier engine; the 2015 Chrysler 300 gets 1.5 more mpg. Among similarities are the body structure, market segment, starting price, ground shadow size, height, and maximum occupancy.