Two Tesla models, but radically different on almost all aspects. First of all, there is a significant difference between body structures and exterior dimensions. The 2017 Tesla Model S is a Sedan, while the 2017 Tesla Model X is an SUV. It is also slightly smaller. Also, the 2017 Model S is priced $14,500 lower compared to the base MSRP of the 2017 Model X. And finally, you get 10.7 more mpg with the Model X than with the Model S. Among similarities are the market segment and maximum occupancy.