Two Sedans with some similarities, but otherwise different in most aspects such as the starting price, fuel economy, ground shadow size, horsepower, height, and maximum occupancy. First of all, there is a $339,725 difference in the base MSRP. The 2016 Rolls-Royce Phantom has a higher starting price than the 2016 Porsche Panamera. Also, the 2016 Phantom has bigger and thirstier engine; the 2016 Panamera gets 6 more mpg. In addition, not only Panamera is significantly smaller, but it's also slightly shorter than the Phantom. And finally, the Rolls-Royce Phantom seats one more passenger than the Porsche Panamera. Among similarities are the body structure and market segment.