not really. the 2.5r has a little more power than the 2.5 ( possibly 3-5 m.p.h.)

go to beaverstick.net
go to videos
go to burn and watch
when the video gets to 2:28 there is a revo (right) and a t-maxx (left) racing and you cansee the difference in the motors.

here is the link
video