I guess there is some advantage to the older bikes. I get 48 on the highway and around 40 in town. That's riding it easy. I get about 45 if I push it hard.

 

Bone stock 07 Ultra. In town I average 38-40 mpg. On the interstate at 75+ mph 2 up with gear and luggage 43-45 mpg. Two lane loaded the same as the interstate doing 55 mph becuase I don't know where the next station is, I have rolled 196 miles and put in 3.8 gallons for 51.3 mpg. I have also run a similar distance on the interstate between fill ups and put in 4.8 gallons. I generally end those runs going slower than 75 though.

 

I get in the low 30's after stage 1. I got high 30's when it was stock.

 

07 Road Glide. 40 around town and I have gotten 51 on the highway running about 65mph. Big sucker added with sert race tuner no exhaust change.

 

At stock set-up I was getting 42 to 45. Then installed the stage 1 including the suggested canned map for the PCIII. Then on advice from Dynojet I hooked the PCIII to my laptop and changed both fuel tables in the zero % columns from +5 value to +10 from 2000rpm all the way up to 6500rpm. The slightly richened mixture eliminated the decel pop. Bike runs great and the heat issues are GONE! I now get 39 - 41 mpg.

 

Better than my truck, so it's all good for me!

 

42.8 mpg combination highway and local

 

I have a Y2K FLHRC, pumped to 95" and poor man's 2 into 1 exhaust. I'm running with no flash or fuel management system other than stock. I clicked 75,000 miles last summer. If I keep it under 79 MPH, I can get between 40 and 44 MPG. If I misbehave and ride over 79 MPH, mileage goes down as speed goes up. Conversely, I can get up to 50 MPG if I don't jack rabbit start and ride 55 MPH. Alas, I didn't get a Road King to drive 55.
Last summer I rode through the San Joaquin Valley with a 40 MPH tailwind. I got almost 50 MPG while traveling at 85 MPH. It was amazing.
One thing I attribute to mileage is adding a drain hose to the breathers instead of blowing crank gasses into the combustion chamber. I got an instant 4 MPG boost.
I was at a stealership last summer and they had little stickers on new bikes that stated 54 MPG. Of course, a salesman hit me up and I asked about the little sticker. He admitted that it must "be a mistake," but walked away from me and didn't do anything to remove it.

 

i have a 09 rg and i am getting about 42 mpg

 

I made a 125.7 mile highway run yesterday, got back and refueled at the same pump. Took 3.13 gallons, so that is 40.16 mpg.

By the way, speed was never over 65mph and rpm was never over 2400.

My normal mix of highway/city gets me about 37mpg.