got the vance and hines setup dresser duals, ovals, and fuel pak setup for my '07 ultra with Amsoil in all three holes.... get between 45 and 49 mpg... average probably 47 mpg. Course I've got nearly 7K miles now on mine and I typically cruise at 70 mph (55 miles one way to the office). Buddy of mine has the RHarts and hes getting about the same with the fuel pak. So I'm a big believer in the thing.
I filled up this afternoon and my mileage is up from 31.5 to 34. That's with only250 miles on the clock. Hell, at that rate,by the time I get 5000 miles on it I should be getting about 100 miles per gallon.
I just got gas at 142 miles and it took 3.2 gallons to fill it. I think my milage is down because it has been on the cooler side when I have been riding it.