Fuel consumption + 0.5 liter?

I have my K1200GT now for 7.000 kilometers. Nothing to complain, perfect bike..... but.........
The BC calls the 98 fuel consumption for example 5.0 liter/100 km. In reality when I calculate at the tank-stop, it's 5.5
When the BC says 5.5 or 6.0 than the real consumption is 6.0 or 6.5 liter / 100 km
Do you have the same experience? BMW is to optimistic!!!
Greetings
The BC calls the 98 fuel consumption for example 5.0 liter/100 km. In reality when I calculate at the tank-stop, it's 5.5
When the BC says 5.5 or 6.0 than the real consumption is 6.0 or 6.5 liter / 100 km

Do you have the same experience? BMW is to optimistic!!!

Greetings