A four-by-four is a vehicle with four wheels on the ground and four wheels capable of driving. It is used for work, recreation, and/or personal transportation. The drive system of a four-by-four usually consists of the addition of a front drive/steer axle and transfer case to the power transmission system of a two-wheel rear-drive vehicle. The transfer case is an auxiliary gearbox which is mounted either directly to the main transmission or remotely to the vehicle chassis. It is connected to the rear drive axle via another propeller shaft. A front driveshaft disconnect is included in the transfer case of a conventional four-wheel-drive system. It converts the system to two-wheel drive by directing power only to the rear axle. The paper covers: 1) Changes in the four-by-four market; 2) the effect of federal regulation on four-wheel-drive vehicle manufacturers; 3) an overview of E.P.A. fuel economy testing; 4) suggestions for reducing vehicle fuel consumption; and 5) a prototype of a fuel-efficient four-wheel-drive vehicle.

  • Supplemental Notes:
    • From the 11-14 December 1978 Meeting.
  • Corporate Authors:

    Society of Automotive Engineers (SAE)

    400 Commonwealth Drive
    Warrendale, PA  United States  15096
  • Authors:
    • Spearman, L W
    • Raffa, J
  • Publication Date: 1978-12

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00195296
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Report/Paper Numbers: SAE 781061
  • Files: TRIS
  • Created Date: Aug 15 1979 12:00AM