Here's an interesting comparison test between two of the most high-end luxury four-door saloons on the market today: the 2013 Maserati Quattroporte and the new Jaguar XJ. Maserati's top of the range 2013 Quattroporte has a 3.8-liter twin-turbo V8 engine that spits out 523 hp and 649 Nm of torque. The new Jaguar XJ has a larger 5.0 liter V8 supercharged engine that develops 375kW. However, when comparing the Quattroporte and the XJ, it's not the power that's the main focus point, but quality and comfort of the vehicle.