It is possible to achieve the same mileage per gallon with the mods you are describing. Shortly after rejetting and the exhaust swap, I took a leisurely ride on the blacktop from my house at 5300ft to Sandia Crest at 10,600ft. I got 74mpg. Sure, I didn't need much throttle coming down the mountain, but I figure it evens out with what I needed going up.

I'm more in the 40-50mpg range now, but some of that can be attributed to a change in riding style. It doesn't matter if I am going from 0-20mph or 0-60mph, for some reason I have to get there as fast as possible now.

If I were to guess, I would imagine that you should have no trouble staying in the 60-65mpg range with the mods you are describing.

 

The only way you get more power is to burn more gas. Jetting and free mods will get more power =more gas. But if you are not getting on it you should be able to get the same milage.

 

In stock form, I get 63.307mpg (I filled up today). Deej, I want one those rack carry boxes. Would be a great addition to the chinese take-out order I do about every two weeks.