RON---- I usually run RB motors outdoors like S7 and ws7. But i would have to say the b5 to me seems to run just as good but with better fuel mileage than the s7 just my personal opinion. About the run time we run 6 min qualifiers and i had about 1/3 of a tank left. The track is a pretty big-- hard packed but not blue groove with a light dust on the outside I was TQ with 12 laps at 6:09. I run a jammin x2 with hobao aluminum clutch shoes and im going to try out some other pipes and go up to a 18 tooth clutch bell instead of the 17 because that motor just accelerated out of the corners like no other motor ive had. If you have any suggestions about clutch shoes i would like to hear what might work better. Im really diggin the B5 though great motor no problems at all yesterday I would buy another one without hesitation!!!!