Two Sedans with more similarities, such as the body structure, ground shadow size, height, and maximum occupancy, than differences, like the horsepower, starting price, and fuel economy. First of all, there is a $1,455 difference in the base MSRP. The 2016 Scion iA has a higher starting price than the 2015 Chevrolet Sonic Sedan. And finally, the 2015 Sonic Sedan has a more powerful engine than the 2016 iA, and it gets 4.8 fewer miles on a gallon of fuel. Among similarities are the body structure, ground shadow size, height, and maximum occupancy.