In stock form the E63 S has enough power to take on models like the M5. It is in fact a fair fight: 603 horsepower vs. 591 horsepower! But what happens when the BMW M5 is updated to deliver around 800 horsepower (well, 789 horsepower to be more exact)? Think about models like MH5 800 developed by Manhart. Well, in this case you need the E63 S to deliver more power too. And it is the same
Manhart that has the solution for you: the ER 800 with its 800 horsepower!