My thunderbird got 46 on trips as a 1600. Now as a 1700 i get 40-42 for a high. But those numbers are only on trips due to no stop and go. Even with a lot of throttle, as long as there are no stops i get that or close. This is where it gets crazy....just by riding in the city where there are a ot of stops it can go down to as low as 31 ! Tho lately thats rare and I usually get 34-35 in the city. As a 1600 i never got less than 38 city (very hard riding) and usually 40-42.
So not bad for a 740 Lb bike with a 1700 engine, but i wish i was averaging better in city now. Guess i can't complain tho for the torque it has, and i DO generally accelerate fairly hard much of the time. I changed to mobil 1 recently and i lost a MPG or 2 tho. Not sure why, as this oil has made the bike run stronger so i would think I shoulda gotten more MPG.