Tre seems to smooth out the throttle response a little and add a little performance as it puts the engine in the 5th gear map where the timing is not retarded. it isn't a HUGE difference IMO, but for the price it seems like a pretty good add on (if you don't care about the indicator). there are tons of threads about TRE's so try a search if you want more info. There is a guy here, Jeffw, who sells tre's and people seem to have great luck with them (including myself). Hope this helps, i don't want to go on about it there are more informative threads to answer any other questions you may have, and i am not a expert by any means.