I THINK IT IS THE WAY I BROKE IT IN , via moto USA I have a long hill at 10 % that I rode up and down, wide open throttle up the hill and 60 mph down the hill closed throttle,. and changed the oil at 26 miles then variable speed from there on,I am about 60,000 km. now, and it runs very well,seems to run better every year,. I picked the hill to break it in because of the transmission, down hill gives more back pressure, to set the rings,.
Many, many factors on brake-in, and fuel economy. I could write a thesis.
1.) break in: If you want the most powerful engine, "break it in fast"... Only for about 50 miles be gentle, then floor and rev it, just VARY a lot. Based on dyno tests and comparisons, THAT is the best method. De Dee did basically the above.
2.) De Dee posted KM/Tank, and that is very realistic. It of course depends how steady or wide open throttle you ride, what speed, elevation or sea level, temperature, humidity, purity of gas, tire pressure, and on, and on, and on; MANY factors! Same bike, different rider, different fuel efficiencies.
3.) The fuel injection has a margin of setting (TPS) and being still in factory specs, but varying fuel consumption up to 10%. US people/mechanics tend to set the bikes on the "richer side", while Europeans set them "on the leaner side". Leaner reflects also in better fuel efficiency, but bears a higher risk of detonation, and with that also possible engine and head gasket damage.
As a tip, and you can see instant results: Run a tank where you consciously try to avoid over 5500 acceleration rpm and ease to the desired speed, even though your end speed may be over 5500 rpm (the lower you keep the rpm consistently, the better the fuel efficiency). Then run a tank where you just open up the throttle and blast up to the desired speed. I bet you will see a very significant difference.
FYI: (US gallons) I varied with the D/T from worst 50 mpg, to "typical average"60-65mpg, to best 70-72 mpg. Just depended on the above.