Firstly, how many miles has the car covered? An engine will still be tight up to 5000 miles and won't be delivering optimum fuel economy. Generally, fuel economy will improve during the first 10,000 miles as the engine loosens up.

Secondly, the fuel consumption test is not a guarantee of of what you can expect. It's there to enable buyers to compare the fuel consumption of similar cars on a like-by-like basis. The tests are carried out on a rolling road in laboratory conditions and some drivers find it difficult to replicate the results in real-world conditions. Others find it easy.

Fuel consumption depends on a range of variables, including driving style, terrain, weather, weight of the vehicle etc. In short, not being able to match the official figures is not grounds for rejecting the car.