ProceduresforTireTreadwearTesting.pdf

TP-UTQG-W-01

U.S. DEPARTMENT OF TRANSPORTATION

NATIONAL HIGHWAY TRAFFIC SAFETY

ADMINISTRATION

PROCEDURES

FOR

TIRE TREADWEAR TESTING

CONSUMER INFORMATION REGULATIONS

PART 575.104

UNIFORM TIRE QUALITY GRADING

ENFORCEMENT

OFFICE OF VEHICLE SAFETY COMPLIANCE

WASHINGTON, D.C.

Revised August 2004 i

TABLE OF CONTENTS

LIST OF ILLUSTRATIONS ........................................................................................................ iii

SECTION I INTRODUCTION

1-1. Responsibilities for Program Administration and Procurement .................................. 1-1 1-3. Purpose and Scope ......................................................................................................... 1-1 1-7. Definitions of Terms ..................................................................................................... 1-1 1-9. Tire Test Program Automatic Data Processing System ................................................ 1-2

SECTION II GENERAL PROCEDURES

2-1. General .......................................................................................................................... 2-1 2-3. Calibration of Measurement and Test Equipment ......................................................... 2-1 2-5. Operating Test Procedure ............................................................................................... 2-2 2-7. Good Housekeeping ....................................................................................................... 2-2 2-9. Test Security .................................................................................................................. 2-2 2-11. Test Forms ..................................................................................................................... 2-2 2-13. Test Program Overview ................................................................................................. 2-3

SECTION III TIRE PREPARATION

3-1. General .......................................................................................................................... 3-1 3-3. Tire Receipt and Handling .............................................................................................. 3-1 3-6. Tire Identification and Marking .................................................................................... 3-1 3-11. Tire Pre-Test Inspection ................................................................................................ 3-3 3-13. Test Rims ....................................................................................................................... 3-3 3-18. Tire Mounting ................................................................................................................ 3-4

SECTION IV VEHICLE PREPARATION

4-1. General .......................................................................................................................... 4-1 4-3. Test Vehicle Identification ............................................................................................ 4-1 4-5. Vehicle Preventive Maintenance Schedule ................................................................... 4-1 4-7. Safety Equipment .......................................................................................................... 4-1 4-9. Vehicle Test Weight ...................................................................................................... 4-1 4-12. Vehicle Wheel Alignment ............................................................................................. 4-2 4-15. Time, Speed, and Mileage Measurement ...................................................................... 4-2

SECTION V TESTING PROCEDURES

5-1. General .......................................................................................................................... 5-1 5-3. Test Convoy .................................................................................................................. 5-1 5-7. Vehicle Repairs ............................................................................................................. 5-1 5-9. Vehicle Storage ............................................................................................................. 5-1 5-11. Treadwear Course Description ...................................................................................... 5-1 5-14. Driving Instructions ....................................................................................................... 5-7 5-16. Tire Break-In ................................................................................................................. 5-8 5-20. Tread Depth Measurement ............................................................................................ 5-8 5-33. Test Series ..................................................................................................................... 5-9 5-40. Test Data ..................................................................................................................... 5-10 5-43. Abnormal Conditions .................................................................................................. 5-10 5-45. Time, Speed, and Mileage Analysis ............................................................................ 5-10 5-47. Tire Disposition ........................................................................................................... 5-10 ii

TABLE OF CONTENTS (continued)

SECTION VI

6-1. General .......................................................................................................................... 6-1 6-3. Receipt of Forms ........................................................................................................... 6-1 6-6. Disposition of Forms ..................................................................................................... 6-1 6-8. Additional Data and Forms ........................................................................................... 6-1 6-10. Treadwear Test Package Procedures ............................................................................. 6-1 6-11. Completing the UTQG Treadwear Summary Sheet ...................................................... 6-1 6-15. Completing the UTQG Treadwear Daily Run Sheet ..................................................... 6-1

APPENDIX A ......................................................................................................................................... A-1

GLOSSARY OF TERMS .................................................................................................................... G-1 iii

LIST OF ILLUSTRATIONS

Figure Page

1 Tire Marking ............................................................................................................................................ 3-2

2. Key Points Along Treadwear Test Course ............................................................................................... 5-3

3. San Angelo, Texas, Vicinity .................................................................................................................... 5-4

4. UTQG Treadwear Test Course (Sheet 1 of 2) ......................................................................................... 5-5

5. UTQG Treadwear Test Course (Sheet 2 of 2) ......................................................................................... 5-6

6. The “Forward X” Rotation Plan ................................................................................................................5-8

7. UTQG Disposition Control Document .................................................................................................... 6-4

8. UTQG Test Assignment Form ................................................................................................................. 6-5

9. UTQG Treadwear Summary Sheet .......................................................................................................... 6-6

10. UTQG Treadwear Daily Run Sheet ......................................................................................................... 6-7

1-1

SECTION I. INTRODUCTION

1-1. RESPONSIBILITIES FOR PROGRAM ADMINISTRATION AND PROCUREMENT

1-2. The U.S. Department of Transportation (DOT), National Highway Traffic Safety Administration

(NHTSA), Office of Vehicle Safety Compliance (OVSC) is responsible for administering the tire quality grade testing program. The procurement of test items is a NHTSA Office of Contracts and Procurement responsibility. No information concerning the standards enforcement testing program will be transmitted to anyone except the NHTSA Contract Technical Manager (CTM) unless specifically authorized by the NHTSA CTM or his superiors. No individuals, other than contractor personnel directly involved in the test program, shall be allowed to witness any tire test unless specifically authorized by the NHTSA CTM or his superiors.

1-3. PURPOSE AND SCOPE

1-4. The manual describes the standardized tire and reporting procedure for independent testing organizations in conformance with Part 575.104 Consumer Information Regulations – Uniform Tire Quality Grading – Treadwear Testing effective April 1, 1979, for Bias Ply Tires, October 1, 1979, for Bias Belted Tires, and April 1, 1980, for Radial Ply Tires. As amendments become effective, this procedure will be modified accordingly. Instructions for test preparation, test performance, recording tire data, and reporting test results are presented in detail in this manual.

1-5. The procedure is not intended to conflict with the requirements set forth in the Uniform Tire Quality

Grading Regulation (UTQG) or any amendments thereto. Any contractor interpreting any part of this procedure to be in conflict with UTQG, or noting any deficiency in it, is required to advise the NHTSA CTM for a resolution of the discrepancy prior to testing.

NOTE

The testing organization is responsible for testing tires to all applicable requirements of this regulation and procedure. The testing organization is responsible for verifying accuracy of all data sheets.

1-6. The UTQG Test Facility in San Angelo, Texas, has been established by the DOT, NHTSA, as the test facility for the UTQG treadwear and traction testing. The test facility is centered on the Goodfellow Air Force Base and the Treadwear Course utilizes the public roadways in the vicinity of San Angelo, Texas, for the established 400-mile test course. The UTQG Test Facility is operated by the OVSC, NHTSA. The UTQG Test Facility Chief has overall responsibility for all operations of the Test Facility.

1-7. DEFINITIONS OF TERMS

1-8. Definitions for all specific technical words and phrases will be found in the Glossary of Terms at the end of this manual. Should any questions arise as to the interpretation of these definitions, contact the CTM.

1-2

1-9. TIRE TEST PROGRAM AUTOMATIC DATA PROCESSING SYSTEM

1-10. The tire compliance test program will use automated data processing techniques. The system is designed to more accurately qualify test results in conformance with UTQG, establish a common language for all program participants, minimize invalid tests, eliminate redundancy of effort, and provide the NHTSA Office of Vehicle Safety Compliance (OVSC) with timely test results and laboratory status information.

2-1

SECTION II. GENERAL PROCEDURES

2-1. GENERAL

2-2. This section presents general laboratory procedures that are either contractually required prior to commencement of testing, or general procedures to be followed in addition to specific test procedures.

2-3. CALIBRATION OF MEASUREMENT AND TEST EQUIPMENT

2-4. Before starting the test program, the contractor shall implement and maintain a measurement and test equipment calibration system in accordance with established calibration practices. Guidelines for setting up and maintaining such systems shall meet or exceed the system described in MIL-C- 45662A, “Calibration System Requirements”.

The calibration system shall be set up and maintained as follows:

1. Standards for calibrating the measuring and test equipment shall be stored and used under appropriate environmental conditions to assure their accuracy and stability.

2. All measuring instruments and standards shall be calibrated by the contractor, or a commercial facility, against a higher order standard at periodic intervals not exceeding six months. Records showing the calibration traceability to the National Institute of Standards and Technology shall be maintained for all measuring and test equipment.

3. All measuring equipment, test equipment, and measuring standards shall be labeled with the following information:

a. Date of calibration

b. Date of next scheduled calibration

c. Name of person who calibrated the equipment

4. A written calibration procedure shall be provided by the contractor which includes, as a minimum, the following information for all measuring and test equipment:

a. Type of equipment, manufacturer, model number, etc.

b. Measurement range

c. Accuracy

d. Calibration interval

e. Type of standard used to calibrate the equipment (Calibration traceability of the standard must be evident.)

2-2

5. The contractor, in a manner that assures the maintenance of established calibration schedules, shall keep records of calibrations for all measuring and test equipment. All such records shall be readily available for inspection when authorized by the NHTSA Contract Technical Manager. The calibration system will need the acceptance of the NHTSA Contract Technical Manager before testing commences.

6. As a minimum, the measurement and test equipment calibration system will encompass:

a. Vehicle speed measuring device

b. Vehicle distance measuring device

c. Vehicle weighing device(s)

d. Vehicle front end alignment equipment

e. Tire pressure gauge

f. Digital probe treadwear measurement (to be calibrated by the UTQG Test Facility)

g. Mechanical dial gauge (backup use only)

h. Tire rim measurement equipment

2-5. OPERATING TEST PROCEDURE

2-6. Before starting the test program, the contractor shall provide a written operating test procedure that includes a step-by-step description of the test methodology used in the program. Where appropriate, the test procedure will include such items as check-off lists and individual worksheets for each testing phase. The NHTSA CTM must approve the operating test procedure before testing commences.

2-7. GOOD HOUSEKEEPING

2-8. NHTSA Contractors will maintain the test vehicles, test fixtures, and instrumentation in a neat and clean condition with test instruments set up in an orderly manner consistent with good test laboratory housekeeping practices.

2-9. TEST SECURITY

2-10. All test specimens shall be protected from grease, oil, solvents, and any other substance that would contaminate the tires and thus adversely influence the results of the test program. The NHTSA Contractor shall provide appropriate security measures to protect the NHTSA test tires from contact with unauthorized personnel during the entire test program, as well as to protect and segregate the data that evolve from testing each tire.

2-11. TEST FORMS

2-12. All report items and test results are entered in black ink, or indelible pen on the forms by the testing organization. A sample set of UTQG Treadwear Test forms appears in Figures 8, 9, 10, 11, and 12.

2-3

2-13. TEST PROGRAM OVERVIEW

2-14. The NHTSA test contractor will receive Course Monitoring Tires (CMTs) and candidate tires (test tires) from the UTQG Test Facility in San Angelo, Texas. The tires will then be labeled, inspected, mounted onto rims, balanced and then placed onto the test vehicle. The test vehicle will be ballasted to achieve the required loading of the tires. The vehicles will be driven over the established 400-mile course utilizing the prescribed driving techniques for a total of 7,200 miles.

After each 800 miles, the tire pressure and tire depth will be measured, the tire position will be rotated, and the vehicle’s front-end alignment will be adjusted where required. At the completion of the test, the wear rates of each tire will be calculated. The candidate tire wear rate will be adjusted to compensate for changes in course severity utilizing the data from the course monitoring tires. Based on the adjusted wear rate, the tire is graded, and the resultant grade is compared with the published grade of the tire manufacturer to determine the accuracy of the UTQG treadwear grade.

3-1

SECTION III. TIRE PREPARATION

3-1. GENERAL

3-2. In addition to the candidate tires, course monitoring tires of the three basic construction types will be received. This section presents procedures for tire receipt, handling, storage, identification, marking, and mounting.

3-3. TIRE RECEIPT AND HANDLING

3-4. Inventory and log-in procedures as detailed in the UTQG Data Manage System will be accomplished by the Test Facility personnel prior to release of the tires to the test contractor.

3-5. The UTQG Treadwear Manager (TWM) will disburse the candidate tires and the course monitoring tires from NHTSA to the contracted testing organization. The TWM will inspect the tires to ascertain that they are acceptable for use when received. The testing organization will insure that the tires are handled with care to avoid cuts, tears, or any condition that may adversely affect test validity.

3-6. TIRE IDENTIFICATION AND MARKING

3-7. The tires will be marked with an inventory number.

3-8. A test number shall be written onto the outboard sidewall of the tire by the contractor utilizing tire paint or tire paint stick and kept legible at all times.

3-9. Test numbers will be provided to the contractor by the NHTSA, OVSC. Test number shall consist of eight characters. The first is a code letter identifying the test type (C = compliance test, B= break-in, R = retest, S = special test, M = monitoring, E = responsive). The second and third are the last two digits of the fiscal year (04 = 2004). The fourth digit is a letter identifying the UTQG test phase (W = treadwear). The next three digits are assigned serially from a block of numbers, and start over at the beginning of a new year. These numbers account, by individual tire, for all tires received by the contractor and further identify the contractor by the different series assigned to each contractor. The next character represents the UTQG tire category (C = CMT, X = candidate, S = Special). The last character is a code letter identifying the test contractor. See Figure 2 for the tire marking requirements.

3-2

Test Type (C – compliance test, B – Break-in, R – re-test, S – special test, M – monitoring, E – responsive)

Year of Test (fiscal for compliance; calendar for monitoring)

UTQG Test Phase (W – treadwear)

Unique Sequence Number (001-999)

UTQG Tire Category (A – ASTM, C – CMT, X - candidate, S – S - special)

Testing Organization

S 92 W 001 X L

Each group of four tires will carry the same test number. The four tires will be individualized with the letter A, B, C, or D.

Figure 1. Tire Marking

3-3

3-10. In addition to the test number, the test car number, and tire position shall be indicated on the tire utilizing white chalk.

3-11. TIRE PRE-TEST INSPECTION

3-12. Prior to mounting the tires, the contractor shall conduct a detailed pre-test inspection. Special attention is required in looking for bead scuffs, radial or lateral mold flow cracks, splice breaks, wire breaks, cavities in bead covering, or over-flow of rubber into mold vents, which could prevent proper tire seating on the test rim. A visual inspection should also be made of the tire’s sidewalls, treads, and inner liner for repair work or any abnormalities. All tire defects noted shall be brought to the attention of the CTM and recorded in the remarks section of the test report form. Tires with defects can only be tested when the contractor receives approval by the CTM.

3-13. TEST RIMS

3-14. All physical dimensions of the test rim shall conform to published dimensions of a standard production rim commercially available. Tires tested in accordance with UTQG must be mounted on a rim with any configuration as shown appropriate for that tire size and designation in an associative table found in publications referenced in the standard, or, alternatively, in a publication issued by the tire manufacturer and distributed to dealers and to the public on request. Applicable publications are published by the following organizations: The Tire and Rim Association, Inc., The European Tyre and Rim Technical Organization, Japanese Industrial Standards, Deutsche Industrie Norm, The Society of Motor Manufacturers and Traders, Ltd., British Standards Institution, and Scandinavian Tire and Rim Organization. Test conformance of each test rim will be verified by physical measurement and visual inspection. The physical measurements taken shall include diameter and width.

3-15. Diameter and width measurements shall be made in accordance with procedures defined in the current TRA Year Book. The diameter will be verified using a mandrel calibrated disk tape or equivalent. The width shall be verified using a TRA Sliding Gauge or equivalent. Tolerances as to diameter or width are as published in the current TRA Year Book for the particular rim involved.

The test rim should have a width within +0.50 -0.0 inch of the width listed. Prior to making measurements, the wheel shall be visually examined for paint runs or any other abnormalities that would cause errors in any reading. All abnormalities shall be removed by light filing, sanding, or by the use of steel wool.

3-16. The measurements shall be recorded and records shall be kept ten years and made available to the

CTM.

3-17. The test rims are to be identified by a contractor assigned serial number that is compatible with the recording requirements as established by these procedures. The serially numbered rims are to be assigned specifically to each tire so that it can be documented that a tire was tested on a specific rim.

Prior to mounting of the test tire on the test rim, the wheel shall be visually checked for obvious deformation of the pilot hole, bolt holes, contours, safety locks, cracks, etc.

3-4

3-18. TIRE MOUNTING

3-19. The test tire shall be mounted on a serially numbered test rim. The rim shall be visually inspected for any apparent characteristics that may affect the test validity. This includes cracks or deformations of the bolt hole, hub, and flange. Those rims which may be in question are not to be saved for UTQG testing. The wheel must be free from any foreign substance, rust, oxidized rubber, or adhesives.

3-20. The tire shall be mounted so that all tire markings are to the outside of the rim and so that the tire identification number is located above the valve stem as shown in figure 2. Exceptions may be made for unidirectional tires, but DOT number should still be aligned with the valve stem if mounted on the side running in. Two of the directional tires that are moving to the fronts will require dismounting and may be flipped over at each rotation to maintain proper orientation. They will also need to be re-balanced.

Mount the tire in such a manner that the beads do not bind against the rim ledge and bend improperly on the rim flange. Do not allow the air pressure to exceed the manufacturer’s prescribed maximum inflation pressure. A thin solution of bead lubricant shall be applied to each bead to aid in the proper positioning and seating of the beads. If the beads have not seated by the time the pressure has reached maximum inflation, deflate the assembly, reposition the tire, and inflate. The pressure gauges shall be accurate within ±1 PSI at the prescribed inflation pressure.

3-21. Any tread irregularities such as mold vent extrusions, shifted shell protrusions, flashing, etc. shall be removed by light buffing to the top of the tire tread rows.

CAUTION

Extreme care should be taken to avoid indenting or burning tread surface during the light buffing operation. If any damage to the tread surface occurs, the tire must be discarded and a replacement tire tested.

3-22. The tires shall be inflated to the test pressure as determined by the maximum load and maximum pressure on tire’s sidewall, using Table 1 on page 950 of the 2003 Federal Register and following the mathematical formula to figure test load and inflation pressure. A record of weights used and their location relative to the I.D. number on each test tire shall be kept.

3-23. The tires will be mounted onto the vehicle in the positions indicated on form UTO-21. See Figure 9.

4-1

SECTION IV. VEHICLE PREPARATION

4-1. GENERAL

4-2. Vehicles for treadwear testing will be supplied by the testing organization.

Air shocks and auxiliary fuel tanks are prohibited.

4-3. TEST VEHICLE IDENTIFICATION

4-4. All test vehicles shall be marked with company identification numbers.

4-5. VEHICLE PREVENTIVE MAINTENANCE SCHEDULE

4-6. The testing organization shall establish a preventive maintenance schedule to maximize vehicle/convoy reliability. The contractor shall present his maintenance schedule to the TWM before the start of each test.

4-7. SAFETY EQUIPMENT

4-8. Each test vehicle shall comply with all applicable Federal Motor Vehicle Safety Standards. All standard safety equipment shall be kept operational at all times. Additional safety equipment shall include flares, fire extinguishers and first aid kits.

4-9. VEHICLE TEST WEIGHT

4-10. With the tires inflated to proper testing PSI the vehicle weight shall be adjusted so that the load on each tire is 85% of the load that is specified in Appendix A of Federal Motor Vehicle Safety Standard 109 for that pressure.

Vehicle weight tolerances for candidate tire vehicles: +0 -2% of specified load. Vehicle weight tolerance for CMT vehicles:

+2 -0% of specified load.

4-11. The vehicle weighing procedure shall be conducted with 250 pounds of ballast in the driver’s position, (200 lbs. in the driver’s seat and 50 lbs. on the floor) and the fuel tank full. Utilization of the vehicle’s fuel gauge to determine the full tank condition is not acceptable. The fuel tank should be topped off.

4-2

CAUTION

Due to the large amount of hysteresis inherent in a vehicle and a vehicle weighing system, it is extremely important that the contractor establish a precise weighing procedure that will guarantee that the results will be repeatable.

4-12. VEHICLE WHEEL ALIGNMENT

4-13. After the tires have been mounted and inflated to the prescribed pressure with the vehicle ballasted with the test load, the front end alignment shall be checked and adjusted if found to fall outside of the manufacturer’s specifications.

4-14. The alignment procedure will be mandatory initially, after tire break-in, and at each measurement of treadwear testing. It shall also be conducted if any situation develops during testing which could possibly change the original wheel alignment.

4-15. TIME, SPEED, AND MILEAGE MEASUREMENT

4-16. The test vehicles shall be equipped to accurately measure and automatically record driving time and speed data. Automatic recording shall be accomplished by the use of a tachograph or similar device.

The automatic recording device shall be calibrated by a method having an accuracy of ±1%.

4-17. The speedometer and odometer on each test vehicle shall be checked prior to commencement of each

1,600-mile segment, to verify that they are registering accurate speed and distance data.

5-1

SECTION V. TESTING PROCEDURES

5-1. GENERAL

5-2. This section describes the test course, the required driving procedures, the tread depth measurement procedures, and all other procedures that are required for the successful completion of a UTQG treadwear test.

5-3. TEST CONVOY

5-4. A test convoy shall consist of a maximum of four vehicles, or a two-vehicle convoy.

5-5. One vehicle of the convoy shall be equipped with four course monitoring tires of the same construction type as the candidate tires. The remaining vehicles will be equipped with the candidate tires. The tires of each vehicle axle must be identical with respect to manufacturer, brand, tire line, and size.

5-6. Each convoy shall be equipped with a CB radio on the first and last vehicle.

5-7. VEHICLE REPAIRS

5-8. In an effort to maintain continuity of the test program, each convoy shall be equipped to make minor on-course repairs where necessary (i.e. fan belts, hoses). If additional parts or assistance is required, arrangements should be made to have a repair service conduct the maintenance on course. In the event that the malfunction requires the vehicle to be removed from the test course, the test tires shall be removed and installed on a qualified replacement vehicle, and the test continued. If a test tire fails on course, it shall be replaced with a dead spare of identical type. The test will continue utilizing only the remaining three tires for data collection.

5-9. VEHICLE STORAGE

5-10. During any non-working hours for any test, the tires and vehicle shall be stored within a secure building.

5-11. TREADWEAR COURSE DESCRIPTION

5-12. The 400-mile course is shown in Figures 3, 4, and 5. On Figure 2, key points along the route are identified by number.

The course consists of three loops as follows.

1. Southern Loop

The southern loop begins at the Convoy Gate and Paint Rock Road (FM388) at the northwest corner of Goodfellow AFB (1). Drive east via FM388 to junction with Loop Road 306 (2).

Turn right onto Loop Road 306 and proceed south and west to junction with US277 (3). Turn

5-2 left onto US277 and proceed south through Eldorado and Sonora (4), continuing on US277 to junction with FM189 (5). Turn right onto FM189 and proceed to junction with Texas 163 (6).

Turn left onto Texas 163; proceed south to Camp Hudson Historical Marker (7) and u-turn in highway. Reverse route to junction of Loop Road 306 and FM388 (2). Food and gasoline can be obtained at Christoval, Eldorado, and Sonora.

2. Eastern Loop

The eastern loop begins at the junction of Loop Road 306 and FM388 (2). Make a right turn onto FM388 and proceed east to junction with FM2334 (13). Turn right onto FM2334 and proceed south across FM765 (14) to junction of FM2334 and US87 (15). Make the u-turn (or, if not running from Goodfellow AFB as a start, proceed to Veribest church and make a u-turn) and return to junction of FM388 and Loop Road 306 (2).

3. Northwestern Loop

The northwestern loop begins at the junction of Loop Road 306 and FM388 (2). Proceed north on Loop Road 306, onto US277, to junction with FM2105 (8). Turn left onto FM2105 and proceed west to junction with US87 (12). Turn right onto US87 and proceed northwest to junction with FM2034 near the town or Water Valley (11). Turn right onto FM2034 and proceed to junction with Texas 208 (10). Turn right onto Texas 208 and proceed south to junction with FM2105 (9). Turn left onto FM2105 and proceed east to junction with US277 (8). Turn right onto US277 and proceed south to junction with FM388 and Loop 306 (2).

Return to start point at Convoy Gate at Paint Rock Road (1). There is food and gasoline at FM2105 and US 87 (12) and along US87.

5-13. The TWM shall provide the testing contractor with instructions as to the sequence in which the above three loops will be driven.

5-3

Figure 2. Key Points along Treadwear Test Course

5-4

Figure 3. San Angelo, Texas Vicinity

5-5

Figure 4. UTQG Treadwear Test Course (sheet 1 of 2)

5-6

Figure 5. UTQG Treadwear Test Course (sheet 2 of 2)

5-7

5-14. DRIVING INSTRUCTIONS

5-15. The drivers shall strictly adhere to the following procedures:

1. Vehicle Speed

The speed to be maintained throughout the course shall be the posted speed limit unless unsafe conditions arise. Under such circumstances, the speed should be reduced to a maximum safe operating speed.

2. Braking Procedures at STOP Signs

There are a number of intersections at which stops are required. At each of these intersections, a series of signs are placed in a fixed order as follows:

SIGN LEGEND

Highway Intersection 1000 (or 2000) feet

STOP AHEAD

Junction XXXX

Direction Sign (Mereta )

STOP or YIELD

PROCEDURE

a. Approach each intersection at the posted speed limit.

b. When abreast to the STOP AHEAD sign, apply the brakes so that the vehicle decelerates smoothly to 20 mph when abreast of the direction sign and make a complete stop at the STOP sign.

3. Vehicle Separation

During the entire test, no convoy vehicle, other than the lead car, shall be out of sight of the preceding vehicle. If, due to a dire situation, the test convoy must be broken, the lead driver shall be notified of the situation.

4. Passing Procedure

When approaching a slow moving vehicle, the convoy lead driver should attempt to safely pass the vehicle and then drop speed slightly and wait for the remainder of the convoy to pass the vehicle. Once all the convoy cars have passed the slow moving vehicle, the lead driver may accelerate to the posted speed limit.

5-8

5-16. TIRE BREAK-IN

5-17. The convoy will be driven over one circuit of the 400-mile treadwear course. At the completion of the first circuit the tires will be rotated utilizing the “Forward X” rotation plan. See Figure below.

Right

RF RR

Front Rear

LF LR

Left

Figure 6. The “Forward X” Rotation Plan

5-18. After the tires have been rotated, the convoy will be driven over the course for one additional circuit, for a total of 800 break-in miles.

5-19. At the completion of the tire break-in, the tires will immediately be removed from the vehicle and prepared for the initial tread depth measurement.

5-20. TREAD DEPTH MEASUREMENT

5-21. The tires will be allowed to cool until the initial inflation pressure is reached or two hours, whichever occurs first.

5-22. Clean the tires to remove accumulated road dirt, stones, or anything that may impair the accuracy of the tread depth measurement. Washing is permissible if needed.

5-23. Utilizing tire paint or tire paint stick, the tire shall be marked radially at six (6) equally spaced locations. The marks shall originate at the shoulder and continue across the tread to the opposite shoulder. The marks shall be located so that the treadwear indicators are avoided. The six locations will be utilized for the tread depth measurement of each tread groove. The first of the six locations shall be in the vicinity of the tire identification number. Note that the shoulder grooves that are not provided with treadwear indicators are not utilized for tread depth measurement.

5-24. Check tire pressure and adjust to specified test pressure if necessary.

5-25. The tires will be inspected and the remaining tread depth will be measured by the testing organization utilizing the hand-held digital probe tread depth gauge. The depth gauge will digitally indicate the remaining tread depth and simultaneously input the information into the computer.

5-9

5-26. The tread depth gauge shall be checked utilizing a calibrated gauge block prior to each use.

5-27. Place the tire onto the measurement stand with the tire identification number facing the operator.

Measurements will be taken at the six marked locations in each successive tread groove (starting with the groove nearest the operator). The measurements will be taken in a clockwise direction (rotate the tire counterclockwise).

5-28. The depth gauge will indicate a three-digit number representing the remaining tread depth in thousandths of an inch. Each of these measurements will be logged in to the computer.

5-29. The tire section width, outside diameter, tread profile, and Shore Hardness will be measured and logged onto the computer once after the break-in phase. Any additional measurements of these parameters will be conducted at the discretion of the CTM.

5-30. The new vehicle tire position shall then be re-marked onto the tread surface of the tire.

5-31. Each tire will be replaced onto the vehicle that it was originally on, except the tire vehicle position will be rotated utilizing the “Forward X” rotation plan.

5-32. The vehicle’s front-end alignment shall be checked and readjusted if necessary.

5-33. TEST SERIES

5-34. Upon completion of the 800-mile tire break-in and the post break-in procedures, the remaining 6,400 miles of the treadwear test will follow in 800-mile increments.

5-35. At the completion of each 800 mile series, all of the tread depth measurement procedures will be repeated as follows:

1. Tire Removal (Ref 5-19)

2. Tire Cleaning (Ref 5-22)

3. Tire Pressure Check (Ref 5-24)

4. Tire Measurement (Ref 5-26 thru 5-29)

5. Tire Marking (Ref 5-30)

6. Tire Rotation (Ref 5-31)

7. Reaffirm that vehicle load has not changed.

8. Vehicle Front End Alignment as specified (Ref 5-32)

5-36. Prior to starting the second through the eight test runs, the convoy order will be changed by placing the last vehicle in the lead position and shifting each other vehicle back by one position. While the vehicle convoy order will be shifting throughout the test, the vehicle driver order shall remain the same.

5-10

5-37. At each 1,600 mile completion, after tires have been measured, tires from vehicle number 1 will be moved to vehicle number 2, vehicle number 2 tires to vehicle number 3, number 3 to number 4 and vehicle number 4’s tires to vehicle number 1. If tires are all the same size, no re-ballasting of vehicles is necessary, but if sizes and loads are different, all vehicles must be re-loaded to the tire’s designated load and the vehicles realigned.

The first 800 miles is considered break-in, and thus the first tire movement from vehicle to vehicle occurs at 2,400 actual test miles.

5-38. After vehicle tire and load change and vehicle re-alignment, the tachograph/speedometer must be re-calibrated for the different tire size.

5-39. The contractor must exercise care during dismounting to avoid damage to the test tires.

5-40. TEST DATA

5-41. In addition to the UTQG test forms, the test contractor is responsible for maintaining additional logs and data sheets that will be required to support the test data.

5-42. As a minimum, the following information and records shall be maintained for each test convoy:

1. Vehicle Maintenance Records (repairs, alignments)

2. Vehicle Weights and Ballasting

3. Vehicle Calibration Information (speed and distance)

4. Convoy Slow-up and Delay Logs

5. Weather and Driving Conditions (including the number of “wet” miles driven)

5-43. ABNORMAL CONDITIONS

5-44. Abnormal conditions encountered while driving the test course, such as tire replacement, mechanical malfunctions, and accidents, shall be reported on a case-by-case basis to the TWM.

5-45. TIME, SPEED, AND MILEAGE ANALYSIS

5-46. The senior testing contractor representative shall review all automatically recorded time and speed data to insure that the course has been driven properly. The representative shall also verify the correct accumulation of mileage per test vehicle. Any deviations noted shall be brought to the attention of the TWM.

5-47. TIRE DISPOSITION

5-48. Upon completion of each test, the contractor representative will return the tested tires to the TWM.

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SECTION VI. REPORT PROCEDURES

6-1. GENERAL

6-2. This section relates to the Treadwear Test Forms, function of the forms, and the supportive data required to be submitted by the contractor to corroborate entries on the test forms.

6-3. RECEIPT OF FORMS

6-4. Upon receipt of each tire set (four tires) from the UTQG test facility, the testing organization will receive a treadwear test package. It is the test contractor’s responsibility to complete the forms neatly and accurately.

6-5. The treadwear data package will consist of one UTQG Tire Disposition Control Document, one

UTQG Test Assignment Form, and, for each test number (a test may have two or four tires), one UTQG Treadwear Summary Sheet, and eighteen UTQG Treadwear Pre-Daily Run Sheets. See Figures 8, 9, 10, and 11.

6-6. DISPOSITION OF FORMS

6-7. Upon completion of all forms for a test series, they will be returned to the UTQG TWM.

6-8. ADDITIONAL DATA AND FORMS

6-9. It is the test organization’s responsibility to supply as much additional data and information as required to back up and substantiate the test data for the treadwear test package sheets.

6-10. TREADWEAR TEST PACKAGE PROCEDURES

6-11. COMPLETING THE UTQG TREADWEAR SUMMARY SHEET

6-12. The contractor will complete the UTQG Treadwear Summary Sheet. Prior to mounting the test tire onto the rim, the test organization technician shall compare the information on the summary sheet with the information actually on the tire. If the information agrees, the technician will then sign the sheet and enter the date. See Figure 9.

6-13. If a discrepancy of information is noted, the TWM shall resolve the problem.

6-14. Upon completion of the tire inspection, the Treadwear Summary Sheet will be returned to the TWM.

6-15. COMPLETING THE UTQG TREADWEAR DAILY RUN SHEET

6-16. Sufficient daily run sheets will be supplied to the test organization for the complete treadwear test.

6-17. Pre-Daily Run Sheet information (see Figure 10) – fields not listed below will be pre-printed.

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1. Circuit Date: date the circuit was started

2. Driver ID: driver’s initials

3. End Time: Enter local 24-hour time at end of circuit.

4. Start Time: Enter local 24-hour time at start of circuit.

5. Total Time: Deduct Start Time from End Time and enter total hours and minutes.

6. End Mileage: Enter Test Vehicle Mileage at end of circuit.

7. Start Mileage: Enter Test Vehicle Mileage at start of circuit.

8. Total Mileage: Deduct Start Mileage from End Mileage and enter completed circuit mileage.

9. Wet Miles: Enter wet miles test tires encountered in this circuit.

10. Mechanical Failure: See UTQG Vehicle Failure Code Listing (Appendix A).

11. Mileage at Failure: Enter vehicle’s mileage at time of failure.

12. Alignment Mileage: Enter cumulative mileage on test tires when vehicle was last aligned.

13. Aligned Date: Enter date vehicle was last aligned.

14. Aligned By: Initials of person who did alignment on the vehicle

15. Actual Load: Enter actual measured load for each tire.

16. Meas. PSI: Enter PSI for each tire before circuit departure.

17. Adj. PSI: Enter PSI if it was necessary to add air to tire.

18. Mid PSI: Enter PSI at the mid-point of the circuit.

19. End PSI: Enter PSI at end of the circuit.

20. Fail Code: See UTQG Tire Failure Code Listing (Appendix A) Manager.

21. Fail Mileage: Enter vehicle’s mileage at time of tire failure

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22. Remark: Enter remarks pertinent to the test circuit, such as:

o Tire replacement number and wheel position in case of tire failure o Mechanical problems and which test convoy vehicle o Any other significant incident

23. Test Organization Representative Signature: Enter Test Organization’s Supervisor’s signature if an entry is made for tire failure or mechanical failure.

24. Driver Signature: vehicle driver’s signature

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Figure 7. UTQG Tire Disposition Document

6-5

Figure 8. UTQG Test Assignment Form

6-6

Figure 9. UTQG Treadwear Summary Sheet

6-7

Figure 10. UTQG Treadwear Pre-Daily Run Sheet

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APPENDIX A. TIRE CHARACTERISTIC CODES

Tread street S

CMT C

Construction tube type T tubeless L bias B belted bias E radial R

Appearance blackwall B other O

(Other: whitewall, raised white letters, red stripe, etc.)

Cord Materials nylon N rayon R polyester P fiberglass F steel S nygen G

Aramid A

Fortiflex* A

DP01* A

* Additional product names for Aramid

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VEHICLE AND TIRE POSITION CODES

Vehicle Positions Tire Positions

Lead position 1 Left front 1

Second position 2 Right front 2

Third position 3 Left rear 3

Fourth position 4 Right rear 4

Spare 5

TIRE FAILURE CODES

01A Labeling

01B Tread separation

01C Bead separation

01D Linear separation

01E Chipping or chunking

01F Splice separation

01G Flat spot

01H Mold fold – row edges, sometimes strip off

01J Flash – mold misalignment

01N Splice opening

01P Groove cracking = Externally produced (by small stone in groove which induces a small cut that propagates – not a product defect.)

01R = Internally produced (due to shallow rubber underbase at groove bottom, compounding of rubber, extreme carcass growth – usually grows in length and depth)

= Always 6-B in a product defect. Tire fails test. Can be isolated to a single tire, but usually all specimens do it.

01S Porosity = Rubber compound aerated due to bag pressure loss during curing - fast wearing tire - single product defect.

01T = Bent or damage beads – tire will not inflate or hold air

01U = Workmanship – irregularities that occur in tire production line whereby tire is damaged

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EXTERNAL AND ENVIRONMENTAL TIRE FAILURE CODES

02A Run FLAT

02B Puncture

02C Valve problems

02D Cuts produced by foreign object

02E Patch lockup

02F Accident

02G Other

VEHICLE SYSTEMS FAILURE CODES

Steering assembly 62A

Suspension 62B

Brakes 62C

Emergency brakes 62D

Engine 62E

Fuel, carburetion, exhaust 62F

Power train 62G

Electrical system 62H

Lighting and communication system 62J

Visual system 62K

Heat, defroster, air conditioner 62L

Vehicle instrumentation 62M

Structure 62N

Electronic system 62P

Rim 62R

Speedometer or tachograph 62S

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TEST EQUIPMENT CODES

Shore Hardness Durometer ID

1. Durometer serial number 55070-A

2. Durometer serial number 43930-A

Surface Thermometer

1. Wahl Infrared Thomometer, serial number1558A

TEST ORGANIZATION CODES

If a testing organization is a tire manufacturer, use his brand or manufacturer code.

A ARA Automotive Research Associates

P APG Automotive Proving Grounds

C CTI Compliance Testing, Inc.

K KJL K.J. Law (PATTCO)

N NAT Nevada Automotive Test Center

M SMI Smithers Scientific Services

S SRI Southwest Research

E STX South Texas Testing

T TTI Transportation Testing, Inc.

R TRC Transportation Research Center of Ohio

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GLOSSARY OF TERMS

Base Course Wear Rate A rate of wear provided by NHTSA for a specific Course Monitoring Tire -used in calculating the Course Severity Adjustment Factor.

Bead That part of the tire made of steel wires, wrapped or reinforced by ply cords, that is shaped to fit the rim

Belted Bias A type of pneumatic tire which features a bias tire construction reinforced with textile ply (belt) at an angle less than the carcass angle, located between the carcass and the tread

Bias Tire A type of pneumatic tire construction which features the ply cords that extend to the beads, laid at alternate angles substantially less than 90° to the centerline of the tread

Brand, Tire The identifying name assigned by the seller of the tire

Break-in The running of a tire prior to test for 800 miles - a stated load/inflation/rotation procedure on a stipulated route to remove any production finishers or excess protrusions and to stretch and stabilize the carcass

Candidate A tire to be tested in a convoy with CMTs to determine the projected mileage and thus a value for stating the relative treadwear grade for the tire

Carcass The tire structure except tread and sidewall rubber

Circuit The complete 400-mile treadwear course consisting of all three loops

CMT Course Monitoring Tire – any one of three construction types (radial, belted bias, or bias) used to evaluate the environmental variations in the treadwear course and thus to determine the Course Severity Adjustment Factor

Construction The reference to the body structure of the tire; the type designator of the tires tested: R-radial, BB-belted bias, b-bias

Contract Technical Manager (CTM) - the designated OVSC official who is responsible for assuring contractor compliance with contractual obligations

Convoy Consists of no more than four vehicles operating in a group, at least one of which is equipped with a set of Course Monitoring Tires

Convoy Order The order from the first to last vehicle in line during a run - the convoy order changes for each run as the last vehicle moves to the lead and the remainder of the cars shift back one position.

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DOT Department of Transportation

FMVSS Federal Motor Vehicle Safety Standard

GFE Government Furnished Equipment

Loop Any one of the three segments of the 400-mile treadwear course starting and ending in the vicinity of Goodfellow Air Force Base at San Angelo, Texas.

The loops are identified as Southern, Eastern, and Northern.

NHTSA/OVSC National Highway Traffic Safety Administration/Office of Vehicle Safety

Compliance

OVSC CC Office of Vehicle Safety Compliance Computer Center

Production Lot An undesignated number of tires, all made of the same supply of raw materials with the same specification in the same production facility, as nearly as possible during the same time (i.e., sequentially without interruption)

Projected Mileage The calculated number of miles a tire will run to the point of being worn out

(to the treadwear indicators)

Radial Tire A type of pneumatic tire in which the ply cords extend to the beads and are aligned substantially 90° to the centerline of the tread

Remaining Tread Depth Average Tread Depth – the thickness of the tread rubber from the tread surface to the base of the grooves, determined by averaging all the groove depths

Rim A metal support for a tire or a tire and tube assembly upon which the tire beads are seated

Rotation Plan The rotation order between wheels and vehicles can vary; in this program, the Forward X plan or pattern was used. See Forward X.

Rotation, Vehicle The changing of vehicle positions within the convoy – see Position, Vehicle

Rotation, Wheel The changing of wheel positions on the vehicle – see Position, Wheel

Run Consists of two 400-mile circuits, or 800 miles of break-in or treadwear testing – eight runs constitute a test series.

Sidewall That portion of a tire between the tread and the bead

Test (also Test Series) Consists of one vehicle operating for eight runs of 800 miles for a total of

6,400 miles – does not include the break-in or previously accumulate mileage

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Test, First or Single Series Same as Test (Test Series) except the tire set has accumulated no mileage, other than break-in, prior to the test start; the first series test, as all other complete test series, must then consist of eight runs.

Test Course The 400-mile roadway specified for use during this program; made up of the

Southern, Eastern, and Northern loops

Test Facility The UTQG Test Facility at Goodfellow AFB, San Angelo, Texas, operated by NHTSA-NVS

Test Number An nine character number which denotes a particular test, performed by one vehicle with its accompanying set of four tires, either course monitoring or candidate

Test Period The calendar…