You can try hooking the Power Commander up to your computer to make sure that it has not dropped the map (it happens). Also maybe replace your spark plugs, wires, fuel filter, clean your air filter, and anything that may be causing restrictions.

 

do you mean a full tank, 5 gals.? or when the light comes on. 3 1/2 gals, big difference.
Why don't U just say 20mpg or 35mpg and then other could see what U mean...

used to get 41 average, now with cams its about 38..

 

Agreed +1 only I used to 41 and now with cams and exhaust 38/36/34 Depending on the day and how I feel fast or slow (aggressive or upstanding citizen).

 

That must be when the light comes on. Mine used to be like that 02 flstf, but there was only a gallon or two of gas to fill it back to full. Your tank is 5 gallons. Check next time you fill up. If you are really only getting that few miles on a full tank,something is seriously wrong. I would unhook the PC and ride a tank without it to see if it makes a difference.

 

I have a 2001 fatboy with longshots and K&N air filter stage 1 download. 47,000 miles and use to get 49 highway and 44 local put a PC III usb on it last month and lost those numbers. I have to really dial it in to get some of that back.....

 

When my light comes on it will only take 3-3.5 gals to fill, I ran it till it said I had 1 mile left and it took 3.8 to fill. take the amount of gas you put in and the miles it went and see what you are getting. I go from mid 40's to high 30's depends how much I twist the throttle

 

I have had tail wind my entire life. Especially after a big dinner while I watch tv. It hasn't helped my milage on my bike or impressed my wife much.

 

i bet the dog liked it