This article discusses some of the difficulties in assessing tyre manufacturers' claims for the new generation of truck tyres with low rolling resistance. For most truck and bus operators, low vehicle operating cost is the main consideration. Tyre cost calculations are usually easy, but calculations become more difficult when tyre specification begins to have large effects on other vehicle running costs such as fuel consumption. It is not easy to balance the cost of a long-life tyre with the cost of a tyre with shorter life that saves fuel. Michelin's Energy tyres are 7% more expensive than the XZA/XDA range that they are intended to replace. Energy tyres have about 20% less rolling resistance and 5% less fuel consumption, though the exact figures depend on road conditions. Michelin's claims for its Energy tyres are based on the performance of a five- or six-axle 38t or 40t combination, running at a constant 80kph (50mph) with Energy tyres on every axle. For lighter vehicles, such as two-axle rigid trucks and coaches, these tyres provide lower savings. There is no simple readily available comparative test for measuring tyre rolling resistance, and the long-established international standard ISO 9948 allows four different methods of measuring rolling resistance, and leaves the choice of method to the tester.

  • Availability:
  • Corporate Authors:

    Institute of Road Transport Engineeers

    1 Cromwell Place
    London SW1 25F,   England 
  • Authors:
    • BUNTING, A
  • Publication Date: 1996-1


  • English

Media Info

  • Pagination: p. 10-1
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00722437
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, ATRI
  • Created Date: Jun 28 1996 12:00AM