Hi Eric, I do not have a speedo healer installed and the front and rear sprockets are both stock. My commute to work is about 8 miles. I get the same number of miles reported on my commute to work whether I am riding my FZ1, car, and my belated FJR (sniffle, sniffle, sob, sob). Given that all three odometers report the same numbers, I am pretty confident the odometer on the FZ1 is accurate. The lowest mpg number I have gotten (I have only ridden the bike about 1200 miles now) is 35. I would not say that I drive aggressively. Most of the time by the time I reach 50 mph, I am in 6th gear. Colorado Springs is a little over 6000 feet above sea level, so you would think that would impact fuel efficiency negatively also.