I have this indication on mine and I happened to top up the tank today.I wonder how accurate that is? I don't suppose you filled up to check?
Where say everything was based on units or multiples of 10 and volumes were based on the density of a commonly occurring substance, such as water?
Ah - those Romans had a lot to answer for?Just don't take my miles away from me ... I lived in Germany for three years, and still had to convert kilometers to miles to appreciate distances.