FLEET managers who are having a hard time convincing 'petrol heads' that diesel engines are no longer the preserve of tractors and HGVs have a further weapon in the form of a booklet titled 'Green About Diesel? The truth behind diesel performance, emissions technology and taxation'. Produced by Delphi Automotive Systems, the 20-page booklet is available free of charge to fleet managers. To obtain copies, call 01295 277050.