I would be surprised if the mpg goes up. On this bike like you said the sweet spot is 70 pluss with the stock gearing and rpms. If you lower the rpms at 70 you might have to cruise at 90mph to get the same mpg as stock,lol. I did a pulley swap with my Roadliner to lower the rpms. My gas mileage was worse on the highway, go figure. I did over 511 miles this past weekend on my FZ10. Average mpg was 36.6mpg. Highway rideing was low 40's at 70mph and above.That really ain't bad at all.The other day, I mistakenly pulled away from a stop, in 3rd gear, no problem. This bike has gobs of torque. Power wheelies all day thru 2nd. Freeway speeds see 5-6k, the sweet spot for MPG, it seems. But even in 6th at 50MPH, the power is still on tap to pull away quickly without a downshift. Could we gear this up slightly? Will our MPG suffer, or possibly improve? Any thoughts?