I have no mods other than drilled baffles. I have gotten near 50 mpg /200 miles before fill up but let me stress that this was extremely careful riding almost at idle keeping it in 4tth and 5th gear as much as possible and costing a lot on down hill stretches. I did this for the purpose of testing maximum mileage. When I filled up it took 4 gal. The tank holds 4.1 gal including the reserve tank. I then did a test by riding it hard and fast racing in lower gears and up mountain roads. It took 3.96 gal at 100 miles /25.25 mpg. So there you have it. Use RoadKills rule of thumb and you should be fine.