A STUDY OF AUTOMATIC TRANSMISSION VEHICLE DRIVE-BY NOISE CHARACTERISTICS

A study of automatic transmission cars with respect to urban driving characteristics and drive-by noise levels is described. The work also included a survey of published data on automatic transmissions, both production and prototype forms and for commercial vehicles as well as cars. Tests on ten pairs of automatic and manual cars over the chassis dynamometer Federal urban drive cycle showed that the automatic car engine speed was on average some 25% less than the manual, reflecting a theoretical 3 dba noise difference on the basis of engine speed. The drive-by tests confirmed this "concession" for the automatic cars, but only for less than half of the sample. The remainder of the sample displayed very large differences from +7 and a half to -7 and a half dba illustrating the wide range of auto transmission characteristics displayed even by conventional epicyclic/torque converter systems. The likely increased adoption of much more advanced continuously variable transmissions will need appropriate amendments to the already limited EEC drive-by test methods. For the covering abstract of the conference see TRIS 451834. (TRRL)

• Supplemental Notes:
  • Vehicle Noise and Vibration. Papers read at the International Conference held at the Institution of Mechanical Engineers, London 5-7 June 1984.
• Corporate Authors:

  Mechanical Engineering Publications Limited

  P.O. Box 24, Northgate Avenue
  Bury St Edmunds, Suffolk IP32 6BW,   England 
• Authors:
  • MORRISON, D
• Conference:
  • Vehicle Noise and Vibration. Papers read at the International Conference held at the Institution of Mechanical Engineers, London 5-7 June 1984.
• Publication Date: 1984

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 7-9

Subject/Index Terms

• TRT Terms: Alternatives analysis; Automatic control; Automatic transmissions; Automation; Automobiles; Conferences; Driving; Manual transmissions; Motors; Noise; Sound level; Speed; Test procedures; Tests; Transmissions; Trucks; Urban areas; Vehicle power plants
• Identifier Terms: European Commission; European Union
• Uncontrolled Terms: Modifications
• Old TRIS Terms: Automobile engines
• ITRD Terms: 3882: Automatic; 1243: Car; 8525: Conference; 1855: Driving (veh); 8303: EU; 1236: Lorry; 9048: Modification; 1334: Motor; 6748: Sound; 6747: Sound level; 5408: Speed; 6255: Test; 6288: Test method; 1333: Transmission (veh); 313: Urban area
• Subject Areas: Environment; Highways; Motor Carriers; Vehicles and Equipment;

Filing Info

• Accession Number: 00451836
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: May 31 1986 12:00AM