What Car? Q&A - Can you explain European fuel figures?

Q: I currently live in Italy and need to purchase an economical car. All the car brochures here quote fuel consumption figures in litres per 100 kilometres (for example, 6.6l/100km), and I have no idea how that translates in terms of miles per gallon. Can you help me with a simple conversion formula?
Roger Davies

A: A figure of 6.6 litres per 100 km is roughly equivalent to 35mpg. To convert fuel consumption expressed in litres per 100 kms to miles per gallon (mpg), divide 282.5 by the litre/100km figure. To convert the other way, divide 282.5 by the mpg figure.