Manufacturers give a fuel economy figure for new cars in litres per 100km for urban, extra urban (i.e. higher speeds) and combined (a mixture of the two). This number is determined via a standardised test which, unfortunately, bears very little resemblance to the type of driving the vast majority of people do. If a vehicle you are looking at purchasing has an indicated fuel economy of 8l\/100km, everyday driving is probably more likely to be around 10l\/100km (this is my experience, after driving and reviewing over 400 cars since 2007).<\/p>\n\n\n\n
However, the manufacturer-supplied figures are good for comparing between models, just not calculating what your expected fuel costs will be.<\/p>\n\n\n\n
Fuel efficiency can be reported in litres per 100km or kilometers per litre (and similarly using miles and gallons).<\/p>\n\n\n\n
Divide the litres it took to refill the tank by the distance travelled and multiply by 100.<\/p>\n\n\n\n
e.g. 60 litres \/ 800km * 100 = 7.5 litres per 100km (expressed 7.5l\/100km)<\/p>\n\n\n\n