I hope i dont do either. Ive been useing the 2.5 for a couple of days now and love the way it pick's up from 1500 rpm @ 3500rpm it really try's to spin all four wheels. It run's out of steam @ 6000rpm were the silver one just keep's pulling. Put the two together i reckon the 2.5 would be gone to aprox 80mph Then the silver one would be all over it. Cant wait to combine the two.