Convert gallon per 100 kilometers to kilometer per litre

Continental Europe states fuel consumption in litres per 100 km, where lower is better; the UK and US use miles per gallon, where higher is better, and Japan, India and much of Latin America use kilometres per litre. The two kinds of figure are reciprocals: 235.2 ÷ mpg (US) gives l/100 km. Mind the gallon: the imperial gallon is 4.546 l, the US gallon 3.785 l, so the same car scores 20 % more mpg in Britain than in America. 6 l/100 km is 39 mpg (US), 47 mpg (imperial) and 16.7 km/l.