What Car? Q&A - How can I match official fuel economy?

Q: I recently bought a nearly new Ford Focus C-Max 1.6 TDCi, but have been unable to get anywhere near the official fuel consumption of 57.9mpg on the combined cycle. How is this figure calculated?
Peter Hawkins

A: In order to ensure consistent results all fuel-efficiency tests are carried out in a laboratory under test conditions.

This means that it is easy to compare cars on paper. However, it also means it is difficult to achieve the same result in real-life conditions, because driving style, hills, wind speed and even having the radio or air-conditioning on will affect a car’ performance.

If a car produces dramatically different figures, it may be worth taking it to a dealership for an inspection.