cappa, I use a 11x5 on my 46 on my nexstar. Tried a 11x6 and a 12x6 and I'm set with the 11x5. Shorter take off's and power to get out of trouble. Yes it will rev more but I don't do full power dives with it. 13300 rpm tached peak. The 12x6 runs 11800 rpm's and the plane just feels sluggish. With my rubber wheels it is closer to 7 pounds so take the weight of your plane and the thickness of your trainer wings into account.