Hi Guys, Just went on a nice sunny 75 degree day cruise. Nice New England country roads with hills & flats. Almost 2 hours, averaged 43MPH, and got 31.2MPG. Only 4 stops and a couple obsticles. One construction delay of a minute and behinda concrete truck for a mile on a hill. Now this was a complete route starting & finishing in the same spot.So I did this same route in the fall and got 27MPG.with the stock muffler. So my suggestion is that if you want to wake up some ponies and get 4 more MPG put on an axleback. Like I said I have the JBA axleback, I wouldn't know if other brands would do the same. These results were off the Message Center which was proven to be accurate.