I am getting between 34 and 39 mpg. We seldom ride under 80mph on our trips. I thought it was GREAT mileage. I brag about it. I must be used to V8 bikes at about 18 mpg.
After some more research outside this forum, it seems most R3s are getting ~34 MPG combined miles. One review site got under 100 miles to a tank on a bone stock bike. It's all about right hand control
I have had mileage as low as the high 20s and as high as 43. The high number was riding tight mountain canyons slowly with a group. Rpm, throttle position and aerodynamics are the keys.