FINAL REPORT SSUURRVVEEYY OONN MMOOTTOORR VVEEHHIICCLLEE TTYYRREESS && RREELLAATTEEDD AASSPPEECCTTSS (ENTR/02/045) prepared by: commissioned by: The European Commission Enterprise Directorate General Unit ENTR/F/5 TÜV Automotive is accredited under DAR-registration number KBA • P 00001-95 to the accreditation body of the Kraftfahrt-Bundesamt, Federal Republic of Germany. Final Report “Motor Vehicle Tyres And Related Aspects” Commissioned by: The European Commission Enterprise Directorate General Prepared by: TÜV Automotive GmbH Authors: Dipl.-Ing. (FH) Walter Reithmaier Dipl.-Ing. (FH) Thomas Salzinger PRELIMINARY REMARK: The investigations within the scope of this survey and the composition of the present report were carried out in all conscience and to the best of our knowledge. As can be seen in the list of references, some sources refer to pages on the Internet. As this medium is subject to fast changes, some references may no longer be found at the addresses given in the list. The list of references represents the state at delivery of the first draft version of this report. ______________________________________________________________ SURVEY ON MOTOR VEHICLE TYRES AND RELATED ASPECTS – 2003 - Page 2 CONTENTS: A: GENERAL PART 0 GLOSSARY OF ABBREVIATIONS................................................................................ 9 1 INTRODUCTION................................................................................................... 11 1.1 BACKGROUND AND PURPOSE............................................................................. 11 1.2 APPROACH ...................................................................................................... 11 B: TOPICAL PART 2 ANALYSIS OF TYRE-RELATED ACCIDENT RESEARCH DATA AND CONTRIBUTION OF TYRES TO HIGHER TRAFFIC SAFETY ...................................................................... 13 2.1 ANALYSIS OF DATA FROM ACCIDENT RESEARCH RELATED TO TYRES ............................... 13 2.1.1 TASK DESCRIPTION ........................................................................................ 13 2.1.2 APPROACH ................................................................................................... 13 2.1.3 PROBLEMS INVOLVED WITH DATA COLLECTION, AVAILABILITY AND QUALITY ............... 15 2.1.4 THE ROLE OF TECHNICAL DEFECTS IN ROAD ACCIDENTS .......................................... 17 2.1.5 DETAILS OF TECHNICAL DEFECTS IN ROAD ACCIDENTS ............................................ 19 2.1.6 RESULTS CONCERNING FAILURES IN TYRE CHECKS WITHOUT PRIOR ACCIDENT .............. 24 2.1.7 CONCLUSIONS AND SUMMARY ........................................................................... 26 2.2 CONTRIBUTION OF THE TYRES TO TRAFFIC AND DRIVING SAFETY FROM A TECHNICAL PERSPECTIVE (PASSENGER CARS)........................................................... 28 2.2.1 STRUCTURAL DAMAGE ..................................................................................... 28 2.2.1.1 RELATED TO APPLICATION AND OPERATION ........................................................ 28 2.2.1.1.1 UNDER-INFLATION/OVERLOADING......................................................... 28 2.2.1.1.2 TYRE AGE/AGING BEHAVIOUR .............................................................. 29 2.2.1.1.3 INCORRECT LOAD/SPEED INDICES ......................................................... 29 2.2.1.1.4 EXTERNAL IMPACTS ........................................................................... 30 2.2.1.2 RELATED TO RETREADING .............................................................................. 30 2.2.1.3 RELATED TO CONCEPT/DESIGN ........................................................................ 30 2.2.2 ROAD PERFORMANCE OF THE TYRE ..................................................................... 33 ______________________________________________________________ SURVEY ON MOTOR VEHICLE TYRES AND RELATED ASPECTS – 2003 - Page 3 2.2.2.1 INFLATION PRESSURE .................................................................................... 34 2.2.2.1.1 CORRECT INFLATION PRESSURE............................................................ 34 2.2.2.1.2 OVER-INFLATION .............................................................................. 35 2.2.2.1.3 UNDERINFLATION ............................................................................. 35 2.2.2.2 RELATED TO CONCEPT/DESIGN ........................................................................ 37 2.2.2.2.1 DECELERATION PROPERTIES ................................................................ 38 2.2.2.2.2 AQUAPLANING PERFORMANCE .............................................................. 40 2.2.2.2.3 CORNERING STABILITY ....................................................................... 41 2.2.2.2.4 GENERAL VEHICLE HANDLING/DRIVING SAFTEY......................................... 41 2.2.3 CONCLUSION ................................................................................................ 44 2.2.4 CONTRIBUTION OF THE TYRES TO TRAFFIC AND DRIVING SAFETY FROM A TECHNICAL PERSPECTIVE (MOTORCYCLES).......................................................................... 46 2.2.4.1 HANDLING AND MANOEUVRABILITY................................................................... 46 2.2.4.2 DRIVING STABILITY ...................................................................................... 47 2.2.4.2.1 WOBBLE (SHIMMY) ........................................................................... 47 2.2.4.2.2 KICKBACK ....................................................................................... 48 2.2.4.2.3 WEAVE........................................................................................... 48 2.2.4.3 BRAKING/ACCELERATING ............................................................................... 49 2.2.4.4 SUMMARY AND CONCLUSION ........................................................................... 49 2.3 SUMMARY OF WORKSHOP MEETINGS...................................................................... 51 2.3.1 MEETINGS WITH REPRESENTATIVES OF TYRE MANUFACTURERS (ETRTO).................... 51 2.3.1.1 MEETINGS WITH REPRESENTATIVES OF PASSENGER CAR MANUFACTURERS (ACEA/VDA) ............................................................................................. 53 2.3.1.2 MEETINGS WITH REPRESENTATIVES OF MOTORCYCLE MANUFACTURERS AND MOTOR CYCLE TYRE MANUFACTURERS.......................................................................... 54 3 RESEARCH OF THE CURRENT AND FUTURE STATE OF TECHNOLOGICAL DEVELOPMENTS WITH RESPECT TO TYRES AND RELATED COMPONENTS AND SYSTEMS ........................................................................................................... 56 3.1 TYRES............................................................................................................ 56 3.1.1 TYRES AND COMBINED SYSTEMS WITH RUN-FLAT TECHNOLOGY ................................. 56 3.1.1.1 TYRES WITH RUN-FLAT-PROPERTIES ................................................................. 57 ______________________________________________________________ SURVEY ON MOTOR VEHICLE TYRES AND RELATED ASPECTS – 2003 - Page 4 3.1.1.2 ADD-ON SYSTEMS WITH RUN-FLAT PROPERTIES ................................................... 58 3.1.1.3 TYRE/WHEEL SYSTEMS WITH RUN-FLAT-PROPERTIES ............................................ 60 3.1.1.3.1 SPECIAL DESIGNATIONS (PAX) ............................................................ 61 3.1.1.4 SUMMARY AND DISCUSSION OF RUN-FLAT-TECHNOLOGY ........................................ 61 3.1.2 PRESSURE WARNING AND MONITORING SYSTEMS................................................... 63 3.1.2.1 PASSIVE/INDIRECT SYSTEMS........................................................................... 64 3.1.2.2 ACTIVE/DIRECT SYSTEMS............................................................................... 65 3.1.2.3 SUMMARY AND DISCUSSION OF PRESSURE WARNING AND MONITORING SYSTEMS ......... 68 3.1.3 PUNCTURE REPAIR SETS .................................................................................. 69 3.1.3.1 INSTANT TYRE SEALANTS ............................................................................... 69 3.1.3.2 PREVENTIVE PUNCTURE SEALANT LIQUIDS .......................................................... 70 3.1.4 TYRE SENSORSING ......................................................................................... 71 3.1.4.1 SIDE-WALL-TORSION SENSOR (SWT)............................................................... 71 3.1.4.2 SURFACE-ACOUSTIC WAVE SENSOR (SAW) ........................................................ 72 3.1.4.3 TYRE IDENTIFICATION CHIPS .......................................................................... 73 3.1.4.4 SUMMARY AND DISCUSSION OF TYRE SENSORING ................................................. 75 3.2 RELATED SYSTEMS AND COMPONENTS.................................................................... 76 3.2.1 ELECTRONIC SYSTEMS FOR IMPROVED VEHICLE CONTROL ........................................ 76 3.2.1.1 ANTI-LOCK BRAKE SYSTEM (ABS) .................................................................... 76 3.2.1.2 BRAKE ASSISTANT SYSTEMS ............................................................................ 76 3.2.1.3 ELECTRONIC TRACTION CONTROL (ETC) ........................................................... 77 3.2.1.4 CORNERING BRAKE CONTROL .......................................................................... 77 3.2.1.5 ELECTRONIC STABILITY PROGRAM (ESP) ..........................................................