Just completed a trip to the South of France covering 2200 miles for the round trip, spread over about 7 days of riding. I travelled alone, but met up for 10 days in Frejus with my wife and younger son who travelled via the TGV (highly recommended).
I kept a record of every fill up (mileage and litres). Having entered all this in to a spreadsheet I can report an average of 49.49 MPG, with a best of 54 MPG and worst of 43 MPG for individual fill ups. Having recently returned to biking after 25 years away, I can confidently state that my riding style would probably be described as fairly sedate, though I do have my moments!
I took a very varied route with less than half on motorways running at the French speed limit of 130 km/h. The rest was on cross country routes where I tried (!) to stick to the limit of 90 km/h. I also took in part of the Route de Napoleon in the Alps and some other mountainous roads between Gap and Clermont Ferrand, so had a lot twisties included.
The bike had done just over 10k miles when I bought it in June. I have removed the O2 sensor and replaced it with a blanking plug, with an O2 eliminator fitted to the sensor wiring, for smoother part throttle running. The bike never missed a beat the whole trip, apart from when it wouldn't start when leaving the hotel in Frejus, which turned out to be an embarrassing case of pilot error, having failed to notice the the kill switch had somehow been moved into the off position.
Fred