RS6-570 hp, M5-507 hp.? BMW builds cars that have the potential to be the most powerful on the market. From 3999 cubic centimeters, they can put out 420 horsepower (BMW M3), and Audi can put out the same power from 4200 cubic centimeters( Audi RS4), so they need a bigger engine for the same power. I think that as far as engines goes, they are the best, so how they make cars that are not the most powerful?

Because they don't need to.. the BMW is a lighter car, so you don't need more hp to achieve the same result...