i have had the TFI installed on my 05 ultra for 5 yrs. i was getting only 30-33 mpg! i talk to the manufacture and they said i had a bad temp. sensor, i changed it and it did not help. i talked to someone else there and they said that i may have the wrong model installed in my bike, there is NO way to tell by looking at them. The tech had me make an adjustment and it seemed to help somewhat, i am getting a little better mileage but still popping when i let off the throttle. Before i made this adjustment i had my bike put on the dyno and it was VERY rich after it got ove about 1800 rpm. it seems a little better but this Sat. i have set an appointment to have the harley screaming eagle super tuner installed it will cost about $800, which is about equal to the $ i have spent on extra fuel over the last 30,000 miles. i will let you know after a couple of weeks if i like my new changes. bye the way if anyone wants to buy a used TFI let me know.