COMPARISON OF ON-ROAD FUEL CONSUMPTION FOR DIESEL AND PETROL CARS

Over recent years, diesel engines have become an acceptable power unit for the private car, offering low fuel consumption, longer engine life and reduced maintenance costs. This report describes a programme of tests conducted at the Department of Transport technology, Loughborough university of technology, on behalf of the transport assessment division, TRRL, and compares the fuel consumption of three vauxhall cavalier cars. These were a 1600 ld diesel car and the 1300 gl and 1600 gl petrol versions. The fuel consumption of the diesel vehicle was compared to the 1300 cc petrol car which had a similar performance, and the two petrol cars were compared to show the effect different engine capacity had on fuel consumption. Seven test drivers participated in the tests which were conducted on a test route in the county of leicestershire, covering all types of driving environments. Results showed that the diesel vehicle used between 4% and 22% less fuel than its 1300 cc petrol counterpart, depending on traffic conditions. A 9% saving in fuel consumption was achieved with a trained driver in urban conditions, with a corresponding decrease of 6%, 9%, 14%, 21% and 36% in average speed, vehicle acceleration, vehicle deceleration, and "toe-down" throttle position and acceleration, respectively. Due mainly to the additional capital investment of the diesel vehicle, an average motorist would have to annually drive over 40,000 km for a comparative running cost saving with the diesel vehicle over its petrol-engined equivalent. This "break-even" distance was reduced to approximately 27,500 km for annual travel over purely urban road types. An analysis of comparative annual operating costs of the diesel and its petrol equivalent, for the range of driver "types" used in the tests, showed that the more fuel efficient drivers had to complete a higher annual mileage to achieve the same savings in the diesel to those obtained by the more "aggressive", less fuel efficient, drivers. The report concludes that nationally, the introduction of equivalent diesel cars could optimally produce an annual 9.6% reduction in petroleum consumption in the transport sector of the economy, giving a 4.6% saving in total petroleum consumption. (a)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/02667045
• Corporate Authors:

  Transport and Road Research Laboratory (TRRL)

  Wokingham, Berkshire  United Kingdom 
• Authors:
  • Redsell, M
  • LUCAS, G G
  • ASHFORD, N J
• Publication Date: 1988

Language

• English

Media Info

• Pagination: 76 p.
• Serial:
  • TRRL CONTRACTOR REPORT
  • Issue Number: CR 7
  • Publisher: Transport and Road Research Laboratory (TRRL)
  • ISSN: 0266-7045

Subject/Index Terms

• TRT Terms: Automobiles; Diesel engines; Driving; Engine displacement; Engine operation; Fuel consumption; Gasoline; Operating costs
• ITRD Terms: 1243: Car; 1314: Diesel engine; 1855: Driving (veh); 3870: Engine capacity; 3850: Fuel; 232: Fuel consumption; 221: Operating costs
• Subject Areas: Energy; Vehicles and Equipment;

Filing Info

• Accession Number: 00483099
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Report/Paper Numbers: 9
• Files: ITRD, TRIS
• Created Date: May 31 1989 12:00AM