Following declining fuel stocks and calls for energy savings, the question whether engineers should pursue short-term objectives of reducing exhaust emissions with stratified charge (SC) engines, or should they take the long term view of conserving energy resources is examined. This short/long term controversy over SC engines is considered to be highly relevant, since the hope that they would reduce exhaust emissions to the eventual levels proposed in the USA would mean the adoption of extra equipment, and with the knowledge that conventional engines seem set to dominate the European scene for many years. A case is reported for the long-term approach, in that development should be concentrated on direct injection SC engines since they can operate on petrol, diesel, and wide-cut gasoline as well as fuel derived from coal. Data provided in support of this approach indicate that the best that can be expected from a carburetted SC engine is approximately 8 per cent reduction in fuel consumption plus a saving of 5 per cent at the refinery due to the lower octane requirement. On the other hand, the direct injection SC engine offers a potential 13 per cent improvement in fuel consumption on the road, together with a 10 per cent reduction at the refinery, giving a total reduction of 23 per cent. A suitable fuel specification is presented in relation to engine efficiency in usage of crude oil - miles/barrel of crude oil, and ongoing research is discussed into coal-based fuels, the search for systems designed to effect low emissions such as the divided chamber sc engine, and the German approach to unscavenged and modified diesel engines. /TRRL/

  • Availability:
  • Corporate Authors:

    Morgan-Grampian Limited

    30 Calderwood Street
    London SE18 6QH,   England 
  • Publication Date: 1976-12-16

Media Info

  • Features: Figures;
  • Pagination: p. 30-32
  • Serial:
    • Volume: 243
    • Issue Number: 6299
    • Publisher: Morgan-Grampian Limited
    • ISSN: 0013-7758

Subject/Index Terms

Filing Info

  • Accession Number: 00174086
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jul 19 1978 12:00AM