Two Sedans with more similarities, such as the body structure, market segment, starting price, fuel economy, ground shadow size, height, and maximum occupancy, than differences, like the horsepower. And finally, the 2015 Audi A4 produces fewer horsepower than the 2016 BMW 3 Series Sedan. Among similarities are the body structure, market segment, starting price, fuel economy, ground shadow size, height, and maximum occupancy.