Well, just like with brushed motors, there are all kinds of brushless motors - some built for high rpm and others are not. Usually brushed motors are rated in "number of turns", and brushless motors in kev (rpm/volt), but for some reason Hobby King doesn't list the kev for these motors I used and instead lists the "turns." In general, higher number of turns means lower top rpm and more torque. Brushless motors with kev of 700 are going to be significantly slower than the stock 380s that come with the tanks we buy.