All manufacturers must comply with the revised test procedures for new car models on sale from January 1, 1998, but in the interim, most are publishing old or new figures - or a combination of the two. This is causing consternation among fleet managers, who say they have no way of comparing like with like in the current 'halfway house' situation. The differences can quite marked - and differences of only a few miles per gallon translate to thousands of pounds per year on the fuel bills of large fleets.

The new test is in two parts - an urban and extra-urban cycle - and includes cold starts, idling and a series of accelerations and decelerations to compare more closely with real traffic conditions. Honda said it was introducing the new figures early because it believes its customers deserve more accurate information about its product, and like Vauxhall and Toyota, Honda will continue to publish old figures for comparison.