I'm afraid to speak from lack of experience , however I have an 09 800R and a 07 800HO . The 09 has 54-5600 on it and I don't plan on doing a " Top End " unless when I comp check it later today it is tired. I know these have a lean midrange but it is over stated. DOO has been building pretty solid 800's for a while. ( IMO ) Don't know too much about the 06 but that is my opinion . As far as the milage ??? I'm the wrong guy to ask, I never get good milage on anything. I get about 10 mpg on my 09 .
