You should be doing better then 31 mpg , my 02 with the power pro,thunder header,and 28 t primary gear is giving me 135 miles on 3.3 gallons of gas.thats mixed riding around town and hwy 70-80 mph.
So your getting 40.9mpg?
I have a Roadglide conversion so that may be of some factor. I weigh 230lbs and my wife is 110... along with the fairing, stereo, speakers, GPS, radar, gauges, saddlebags and brackets, rider and passenger floorboards, engine guard, etc... There is probably somewhere around 400lbs added to the weight of the bike.
Out here in west Texas the speed limit is 80 mph and we tend to run well past that so yea... I guess my 31mpg is normal with the 28 tooth front pulley. I am planning to grab a 30 tooth and see if it will work with a stock length belt. If it will, I will try that for awhile.
The funny thing is... my actual Roadglide with a 96" motor and a 6 speed gets 42mpg with all other factors being the same.
Just wanted to throw in on this Tuner. I bought mine off ebay for $125 new because someone couldnt install it "they tried but didnt succeed". I installed it along with my K&N filter and tab slash cuts and cranked right up, rode smooth. Definitely more horsepower and the exhaust didnt smell like fuel like before the tuner. No popping on decel during normal driving but a little with full throttle action and having to slow down fast because of i4sland tourist traffic.
I've used the Cobra and Power Commander V and I get better performance results from the Cobra. I've used many different maps and suggestions from Fuelmoto, but have gotten smoother power, more torque, and cooler temps w/ the Cobra. Apparently, as I was exiting the freeway and downshifted gears, my friend claimed a blue fireball shot out of my exhaust. I am using a Bassani Road Rage II B1 Long exhaust, K&N Air filter, and the Cobra FI2000 PowrPro Autotuner.