What is the difference between the Audi A8 50 and 55 models?

I'm interested in purchasing an Audi A8, but I'm not sure what the difference is between the 50 and 55 models. Can someone explain?

The main difference between the Audi A8 50 and 55 models is the engine size and power output. The A8 50 has a 3.0L V6 engine and the A8 55 has a 4.0L V8 engine, resulting in a higher horsepower and torque in the 55 model.

Aside from the engine, the Audi A8 50 and 55 models have similar features and technology. However, the 55 model also comes with adaptive air suspension and all-wheel steering for added performance and comfort.