An account is given of an experiment carried out by the brewing company Bass to compare fuel consumption in leaded and unleaded petrol. Two identical Vauxhall Cavaliers were subjected to a number of tests covering different types of driving, e.g. fast motorway and stop-start urban on the Motor Industries Research Association's circuit. Fuel consumption measurements were made by weighing the test tanks provided. Each car was retuned to run on unleaded petrol by retarding the ignition timing by 4 degrees. One car responded well with fuel consumption no different except with stop-start urban driving when an increase of 4.5% was seen. The other car showed and increase in consumption of 10% rising to 12% with easy cruising. It is concluded that even ostensibly similar engines respond differently to tuning. Tuning procedure could be more exact and refer to a more sophisticated measure. It is suggested however that with current pricing, average fuel consumption has to be 7% more to favour leaded petrol. (TRRL)

  • Availability:
  • Corporate Authors:

    Institute of Road Transport Engineeers

    1 Cromwell Place
    London SW1 25F,   England 
  • Publication Date: 1990-4


  • English

Media Info

  • Pagination: p. 14
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00609757
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jun 30 1991 12:00AM