I know that it will give better mileage and some additional hp. The thing does have a 60hp chip. The chip makes it run like a large block gas engine.
I had read somewhere else about the increased mpg. I guess that the only way to find out for sure is to do it yourself.
I tok this thing on a raod trip from GA to TX. I left Ga w/the tank topped off. I stopped in longview TX to fill up & still had fuel left in the tank. I set the cruise on 70-72 mph. I got 21.5 mpg on the interstate trip stopping only at 3-4 rest stops. It was embarressing 'cause the 18 wheelers were passing me.