These two BMW X3 models are two types of the same model with one major difference, the powertrain. First of all, the is 3 model years newer than the . Also, the 2013 X3 has a more powerful engine and gets 7.5 mpg less than the 2016 X3 Diesel. Among similarities are the body structure, market segment, starting price, ground shadow size, height, and maximum occupancy.