As good as the old C6 ummm. The RB B9 same thing basicly and the new RB B10 Better than the old C6 has better block and better head for cooling everything esle is the same. Great powerband/ runtime always loved the Rb C6 line of motors. The cross 10 has Great power in a buggy reminds you of a C6 in ways and get better gass mileage due to being a 3 port instead of a 5port. Speedy