Depending on how I ride - and I sometimes have a right wrist problem

- I get about 46-48 mpg on the road. I have gotten as much as 52 mpg - before ethanol fuel. Around town, I get 39-42 mpg. On a trip with saddles bags, two duffles strapped on, and riding at 75-80 mph, I get 43-44 mpg. I get about the same two up. My mileage dropped 3 mpg with the advent of ethanol.
Fill your bike right to metal insert in the fuel neck. Set your trip meter to zero. Ride at least 75 miles or more before you refuel. Refuel filling it to the same level as before and compute your mpg. Then zero the trip meter.
Just for information, the speedometers are 5% to 10% optimistic (deliberately calibrated that way); but the odometer is spot on. My T100 speedometer is 9% optimistic. The speedometer on my T100 with the sidecar is about 8% optimistic.