[Federal Register Volume 72, Number 166 (Tuesday, August 28, 2007)]
[Rules and Regulations]
[Pages 49207-49212]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-16934]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2007-29083]


Federal Motor Vehicle Safety Standards; Tires

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation.

ACTION: Final rule; technical amendments; response to petitions for 
reconsideration.

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SUMMARY: In June 2003, NHTSA published a final rule establishing 
upgraded tire performance requirements for new tires for use on 
vehicles with a gross vehicle weight rating of 10,000 pounds or less. 
In January 2006, NHTSA published a final rule; response to petitions 
for reconsideration, which modified certain performance requirements to 
better address snow tires and certain specialty tires. This document 
responds to a petition for reconsideration of the January 2006 rule. 
After carefully considering the issues raised, the agency is denying 
the petition. We are also making a number of technical corrections in 
several tire-related Federal safety standards.

DATES: The amendments in this rule are effective September 1, 2007. 
Voluntary compliance is permitted before that date. If you wish to 
submit a petition for reconsideration of this rule, your petition must 
be received October 12, 2007

ADDRESSES: Petitions for reconsideration should refer to the docket 
number and be submitted to: Administrator, National Highway Traffic 
Safety Administration, 1200 New Jersey Avenue, SE., West Building, 4th 
Floor, Washington, DC 20590. Please see the Privacy Act heading under 
Regulatory Notices.

FOR FURTHER INFORMATION CONTACT: For technical and policy issues, 
contact George Soodoo, Office of Crash Avoidance Standards, by 
telephone at (202) 366-2720, or by fax at (202) 366-4329.
    For legal issues, contact Rebecca Schade, Office of the Chief 
Counsel, by telephone at (202) 366-2992, or by fax at (202) 366-3820.
    Both persons may be reached by mail at the following address: 
National Highway Traffic Safety Administration, U.S. Department of 
Transportation, 1200 New Jersey Avenue, SE., Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Summary of Final Rule; Technical Amendments; Response to Petition 
for Reconsideration
II. Background
III. Petition for Reconsideration
IV. Discussion and Analysis
V. Technical Corrections to the Regulatory Text
VI. Effective Date
VII. Rulemaking Notices and Analyses
VIII. Regulatory Text

I. Summary of Final Rule; Technical Amendments; Response to Petition 
for Reconsideration

    This final rule makes several technical corrections and amendments 
to the regulatory text of Federal Motor Vehicle Safety Standard (FMVSS) 
Nos. 109, 110, 119, and 139, all of which are tire-related standards. 
This final rule also denies a petition by Advocates for Highway and 
Auto Safety (Advocates) for reconsideration of the January 2006 final 
rule; response to petitions for reconsideration, regarding the agency's 
requirements with respect to the endurance test for snow tires.

II. Background

    The Transportation Recall Enhancement, Accountability, and 
Documentation (TREAD) Act, Section 10, ``Endurance and resistance 
standards for tires,'' required NHTSA to revise and update FMVSS No. 
109, New pneumatic tires, and FMVSS No. 119, New pneumatic tires for 
vehicles other than passenger cars.\1\ In response to this mandate, 
NHTSA published a final rule on June 26, 2003, establishing FMVSS No. 
139, New pneumatic radial tires for light vehicles, which will apply to 
new tires used on light vehicles; i.e., vehicles with a gross vehicle 
weight rating (GVWR) of 10,000 pounds or less, except motorcycles and 
low speed vehicles.\2\
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    \1\ Pub. L. 106-414, November 1, 2000, 114 Stat. 1800.
    \2\ 68 FR 38115 (June 26, 2003); Docket No. NHTSA-2003-15400.
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    The new standard is scheduled to become effective on September 1, 
2007. It features substantially more stringent high speed and endurance 
tests, and a new low-pressure performance test. The purpose of the new 
and more stringent requirements is to improve the ability of tires to 
withstand the effects of tire heat build-up and severe under-inflation 
during highway travel in fully loaded conditions. Unlike the existing 
tire safety standards, which previously differentiated between light 
trucks and passenger cars,\3\ FMVSS No. 139 applies to tires used on 
both.
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    \3\ Historically, FMVSS No. 109 applied to tires for passenger 
cars, and FMVSS No. 119 applied to tires for use on all other 
vehicles, including light trucks.
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    In a January 2006 final rule; response to petitions for 
reconsideration,\4\ the agency reduced the test speed for the tire 
endurance and low-inflation pressure performance tests in FMVSS No. 
139, paragraphs S6.3.1.2.3 and S6.4.1.2.1, from 120 km/h (75 mph) to 
110 km/h (68 mph) for all passenger car snow tires and light truck snow 
tires with load ranges of C, D, and E. The other test parameters--
inflation pressure, duration, load, and ambient temperature--remained 
unchanged.
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    \4\ 71 FR 877 (Jan. 6, 2006); Docket No. NHTSA-2005-23439.
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    For snow tires, the endurance test is a 34-hour test conducted at a 
speed of 110 km/h (68 mph) with a tire inflation

[[Page 49208]]

pressure that is 25 percent below the maximum inflation pressure of the 
tire, and with tire loads of 85 percent, 90 percent, and 100 percent of 
maximum load. After the snow tire has completed the endurance test, it 
is then subjected to a new low pressure test for 90 minutes at an 
inflation pressure about 42 percent below the tire's maximum inflation 
pressure at a test speed of 110 km/h (68 mph) with 100 percent of 
maximum load. The snow tire must complete both the endurance test and 
the low-inflation pressure test without any failures.
    The agency made these changes because of practicability concerns. 
Snow tires are designed with more flexible (i.e., softer rubber) tread 
compounds, which are good for finding traction in snow but can pose 
difficulties for passing certain tire performance tests, because the 
tread designs and compounds are less able than other tires to withstand 
the heat caused by the severity of testing on the road wheel. NHTSA 
determined that the technical design challenges and the costs to 
redesign existing snow tires to pass the new 120 km/h (75 mph) test 
would far outweigh the negligible safety benefits associated with that 
redesign.
    The final rule also changed the effective date from June 1 to 
September 1, 2007, to correspond with the start of the industry model 
year, and to September 1, 2008 for snow tires.

III. Petition for Reconsideration

    NHTSA received one petition for reconsideration from Advocates for 
Highway and Auto Safety (Advocates) on the January 2006 final rule; 
response to petitions for reconsideration.\5\
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    \5\ Docket No. NHTSA-2006-23439-3.
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    Advocates petitioned the agency to reconsider the revised 
requirements related to the endurance test for snow tires in FMVSS No. 
139. According to Advocates, millions of motorists travel with 
dedicated snow tires at high speeds on what are often clear roads, free 
of snow and ice. The petition stated that recent speed studies show 
that increasing percentages of drivers regularly exceed even Interstate 
speed limits posted at 75 miles per hour. Advocates argued that instead 
of requiring manufacturers to improve their snow tire design and 
performance to better withstand the high speeds and temperatures 
commonly encountered in high-speed travel on U.S. highways, NHTSA has 
``grandfathered'' existing snow tire safety design and performance by 
reducing compliance requirements. Advocates disagreed that this 
decision by the agency meets the intent of the TREAD Act.

IV. Discussion and Analysis

    Currently, the endurance test for passenger car snow tires, 
included in FMVSS No. 109, New pneumatic tires, is conducted at a test 
speed of 80 km/h (50 mph). For light truck (LT) snow tires, the current 
endurance test is included in FMVSS No. 119, New pneumatic tires for 
vehicles other than passenger cars, and is conducted at a test speed of 
80 km/h (50 mph) for load range ``C'' and ``D'' tires, and at 64 km/h 
(40 mph) for load range ``E'' tires. The change in endurance test speed 
to 110 km/h (68 mph) in the new FMVSS No. 139 is a speed increase of 38 
percent for passenger car snow tires and LT snow tires load ranges C 
and D, and 72 percent for LT snow tires load range E. These changes 
represent a substantial increase in the stringency of the endurance 
test from the current standards.
    FMVSS No. 109 also includes a high speed test for all passenger car 
tires, including snow tires, with test speeds of 121 km/h (75 mph), 129 
km/h (80 mph), and 137 km/h (85 mph), for 30 minutes at each speed 
step. LT tires, including snow tires, are not currently subject to the 
requirements of a high speed test under FMVSS No. 119. FMVSS No. 139 
includes a high speed test for all light vehicle tires, including snow 
tires, at test speeds of 140 km/h (87 mph), 150 km/h (93 mph), and 160 
km/h (99 mph), for 30 minutes at each speed step.\6\ These changes also 
represent a substantial increase in the stringency of the high speed 
test from the current standards.
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    \6\ We note that the miles per hour (mph) values listed in this 
sentence are not included in the regulatory text of FMVSS No. 139, 
which lists only the metric speed values in S6.2.1.2.7.
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    In the final rule; response to petitions for reconsideration, NHTSA 
explained its determination that because of the nature of snow tire 
construction, the test speed specified in the June 2003 final rule for 
the endurance and low-inflation pressure tests \7\ created 
practicability problems for these tires. Snow tires usually feature 
higher hysteretic tread compounds,\8\ molded in greater tread depths 
and smaller tread blocks than non-snow tires. This construction is used 
to provide special performance in snow conditions.\9\
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    \7\ The June 2003 final rule for FMVSS No. 139 also added a 
brand-new low-inflation pressure performance test, which no standard 
had previously contained. As a brand-new test, that addition to 
FMVSS No. 139 also represented a rise in the stringency of the 
standard over the current standards.
    \8\ In plainer English, this means that since snow tires are 
designed to operate in low ambient temperatures, the tread compound 
tends to be softer to enhance traction. Because it is softer and 
more pliable, as opposed to harder and more durable (like normal 
road tires), the tread compound is less able to withstand the high 
temperatures experienced on the road wheel during testing, which 
leads to pieces of tread rubber chunking off the tire.
    \9\ Deeper treads with smaller surface areas contacting the 
ground help in snow (and other low traction situations) because they 
are able to push deeper through the snow to find traction--not 
entirely unlike, for example, the advantage of wearing shoes with 
cleats on a wet sports field.
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    These tread designs and compounds are disproportionately affected 
at high speeds when tested on a laboratory road wheel. Research 
conducted by the ASTM International has shown that tires tested on a 
curved road wheel experience an increase in severity (in terms of 
stress and temperature) of about 12 percent compared to on a flat 
roadway. A snow tire that experiences chunking \10\ from a 120 km/h (75 
mph) road wheel test does so in part because of the relative severity 
of the road wheel as compared to the conditions on a flat roadway at 
the same speed.
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    \10\ ``Chunking'' is defined as the breaking away of pieces of 
the tread or sidewall rubber.
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    The purpose of the endurance test is to evaluate the tire's 
performance for an extended time period. The test is conducted at loads 
of 85 percent of the tire's maximum load rating for 4 hours, at 90 
percent for 6 hours, and at 100 percent for another 24 hours, for a 
total test time of 34 hours. In addition, the test inflation pressure 
is set at 25 percent below the tire's maximum inflation pressure. These 
are severe conditions for loading and under-inflation, especially given 
that a 100-percent load on the test road-wheel equals about a 112-
percent load on a flat surface. From a real world perspective, this 
means that for the last 24 hours of the test, the tire is 12 percent 
overloaded and 25 percent under-inflated at a test speed of 110 km/h 
(68 mph). Moreover, the ambient temperature for the endurance test is 
38 [deg]C (100 [deg]F).
    Following the endurance test, the snow tire is subjected to a low 
pressure test, which is a new test for light vehicle tires. The purpose 
of the low pressure test is to ensure that the tire can be operated for 
90 minutes at a speed of 110 km/h (68 mph), at an inflation pressure 
about 42 percent below the tire's maximum inflation pressure, with a 
load of 100 percent of the tire's maximum load rating.
    FMVSS No. 139 also includes a 90-minute high speed test at speeds 
of 140 km/h (87 mph), 150 km/h (93 mph), and 160 km/h (99 mph) for all 
tires to which the standard applies, including snow tires. The purpose 
of the high speed test

[[Page 49209]]

is to evaluate the tire's performance during high speed operation, 
which makes this test more directly related to the high speed driving 
to which Advocates referred in its petition. The high speed test 
parameters also include a load of 85 percent, and an inflation pressure 
of about 10 percent below the tire's maximum inflation pressure. This 
test is the same for all light vehicle tires, including snow tires.
    Snow tires are generally operated on vehicles during the winter 
season when ambient temperatures are below 10 [deg]C (50 [deg]F). This 
real world ambient temperature is considerably lower than the ambient 
test temperature of 38 [deg]C (100 [deg]F); i.e., the test condition is 
much more stringent than the likely real world condition. NHTSA 
believes that the upgraded high speed and endurance tests, and the new 
low pressure test in FMVSS No. 139, represent a significant increase in 
performance for light vehicle snow tires as compared to the 
requirements in FMVSSs No. 109 and 119.
    Agency decision: NHTSA has decided to deny the petition from 
Advocates to increase the test speed for the endurance and low-
inflation pressure performance tests for snow tires from 110 km/h (68 
mph) to 120 km/h (75 mph).
    As originally drafted, the test speed for these two tests was set 
at 120 km/h (75 mph). Based on analysis of agency research and testing, 
as well as testing conducted by industry groups and Transport Canada, 
NHTSA reduced the test speed from 120 km/h (75 mph) to 110 km/h (68 
mph) for all passenger car snow tires and LT snow tires with load 
ranges of C, D, and E. As the response to petitions for reconsideration 
described, ``The technical design challenges and the costs to redesign 
existing snow tires to pass the 120 km/h (75 mph) test would far 
outweigh the negligible safety benefits associated with that redesign. 
By reducing the * * * test speeds from 120 km/h (75 mph) to 110 km/h 
(68 mph) * * * we can ensure virtually all the safety benefits from 
upgrading the test speed for snow tires and eliminate practicability 
and cost concerns.'' \11\
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    \11\ 71 FR 880 (Jan. 6, 2006).
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    The agency believes that this decision is sound. Advocates provided 
no data to support its argument that changing the test speed from 120 
km/h (75 mph) to 110 km/h (68 mph) for snow tires would result in 
reduced safety for the public when motorists operate their vehicles 
with snow tires at high speeds for long periods of time. Advocates 
focused on the endurance test, but did not mention that FMVSS No. 139 
includes an upgraded high speed test with speeds up to 160 km/h (99 
mph). The endurance test, moreover, assesses the long-term durability 
of the tire when tested on the road-wheel for 34 hours straight in a 
significantly under-inflated condition.
    The snow tires that NHTSA tested to the endurance and low pressure 
performance tests in FMVSS No. 139 experienced primarily chunking 
failures on the curved test road-wheel. Chunking, defined as the 
breaking away of pieces of the tread or sidewall rubber, occurs during 
testing on the curved road-wheel because the road-wheel heats the tire 
by deflecting its outer edges more than would typically occur when 
tested on a flat surface. In addition, the tread compound, the greater 
tread depth, and the smaller tread blocks used on snow tires make them 
more susceptible to chunking failures.
    NHTSA believes that the combination of tests in FMVSS No. 139, 
which tests at increased stress and higher temperatures due to road-
wheel curvature--the upgraded high speed test, the upgraded endurance 
test, and the new low pressure test--represents increases in test 
severity for snow tires that will result in overall enhanced 
performance as compared to the current levels of testing. Therefore, 
NHTSA believes that the rule clearly meets the intent of the TREAD Act, 
which directed NHTSA to revise and update FMVSS Nos. 109 and 119.

V. Technical Corrections to the Regulatory Text

    1. The agency believes that the tire safety standards should be 
clear and as consistent as possible with one another. FMVSS No. 110 
uses the terms ``light truck (LT) tire'' and ``passenger car tire'' 
without specifically defining them. Therefore, FMVSS No. 110 is being 
amended to add the same definitions for ``light truck (LT) tire'' and 
``passenger car tire'' as are used in FMVSS No. 139.
    2. In the June 2003 final rule, the agency included a new paragraph 
S4.2.2.3(b) in FMVSS No. 110, stating that ``For vehicles equipped with 
LT tires, the vehicle normal load on the tire shall be no greater than 
94 percent of the load rating at the vehicle manufacturer's recommended 
cold inflation pressure for that tire.'' The National Association of 
Trailer Manufacturers (NATM) and the National Marine Manufacturers 
Association (NMMA) submitted a ``petition for clarification'' to the 
agency requesting confirmation that S4.2.2.3(b) was not intended to 
apply to trailers. The agency agrees that it was not intended to apply 
to trailers, which typically have no designated seating positions. We 
note that the definition of ``vehicle normal load on the tire'' in S3 
of FMVSS No. 110 states that ``* * * load on an individual tire * * * 
is determined by distributing to each axle its share of the curb 
weight, accessory weight, and normal occupant weight (distributed in 
accordance with Table I) and divid[ed] by 2.'' We believe that the 
inclusion of ``normal occupant weight'' in the definition of vehicle 
normal load on a tire is an indication that S4.2.2.3(a) and (b) do not 
apply to trailers. To make the standard clearer, the agency is amending 
S4.2.2.3(a) and (b) of FMVSS No. 110 to exclude trailers that have no 
designated seating positions from the category of vehicles to which the 
paragraph applies.
    3. In the January 2006 final rule, the agency sought to make clear 
that temporary spare tires would not be subject to the requirements of 
the new FMVSS No. 139 (but would instead continue to be subject to the 
requirements of FMVSS No. 109), by removing references to T-type 
temporary spare tires from the regulatory text of FMVSS No. 139. To 
better clarify this, the agency is amending S2, Application, of FMVSS 
No. 109 to include T-type temporary spare tires; the first sentence of 
S4.1(a) of FMVSS No. 110 to state that T-type temporary spare tires are 
subject to FMVSS No. 109; and S2.1, Application, of FMVSS No. 139 to 
exclude T-type temporary spare tires.
    4. Since the January 2006 final rule was published, the agency has 
identified several typographical errors in Tables II and III of FMVSS 
No. 119, and is therefore revising and republishing the tables to 
correct those mistakes.
    5. In the January 2006 final rule, FMVSS No. 139 was amended to 
remove references to CT tires because those tires are no longer being 
offered for sale in the United States. Because the January 2006 final 
rule failed to also make conforming changes to S3, Definitions, and 
S5.2, Performance requirements, of FMVSS No. 139, the agency is now 
amending those paragraphs to remove other references to CT tires.
    6. In the January 2006 final rule, subparagraph (i) was added to 
S5.5, Tire markings of FMVSS No. 139, to specify requirements for snow 
tires marked with the ``alpine symbol.'' Because the January 2006 final 
rule failed to also make a conforming change to the introductory 
paragraph of S5.5, the agency is now amending that paragraph

[[Page 49210]]

to account for this additional subparagraph.
    7. A number of typographical errors were found throughout S6, Test 
procedures, conditions, and performance requirements, of FMVSS No. 139, 
and are being corrected in this final rule.

VI. Effective Date

    The effective date of these amendments is September 1, 2007.

VII. Rulemaking Notices and Analyses

    This rule makes a number of technical corrections to the regulatory 
text of several Federal tire safety regulations, and has no impact on 
the regulatory burden of manufacturers. The agency discussed the 
relevant requirements of Executive Order 12866, the Department of 
Transportation's regulatory policies and procedures, the Regulatory 
Flexibility Act, the National Environmental Policy Act, Executive Order 
13132 (Federalism), the Unfunded Mandates Act, Civil Justice Reform, 
the National Technology Transfer and Advancement Act, and the Paperwork 
Reduction Act in the June 2003 and January 2006 final rules cited 
above. Those discussions are not affected by these technical 
amendments.

Privacy Act

    Please note that anyone is able to search the electronic form of 
all documents received into any of our dockets by the name of the 
individual submitting the document (or signing the document, if 
submitted on behalf of an association, business, labor union, etc.). 
You may review DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (Volume 65, Number 70; Pages 
19477-78), or you may visit http://dms.dot.gov.

VIII. Regulatory Text

List of Subjects in 49 CFR Part 571

    Motor vehicles, Motor vehicle safety, Reporting and recordkeeping 
requirements, Tires.

0
In consideration of the foregoing, part 571 is amended as follows:

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

0
1. The authority citation for part 571 continues to read as follows:


    Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
delegation of authority at 49 CFR 1.50.

0
2. Section 571.109 is amended by revising S2 to read as follows:


Sec.  571.109  Standard No. 109--New pneumatic and certain specialty 
tires.

* * * * *
    S2 Application. This standard applies to new pneumatic radial tires 
for use on passenger cars manufactured before 1975, new pneumatic bias 
ply tires, T-type spare tires, ST, FI, and 8-12 rim diameter and below 
tires for use on passenger cars manufactured after 1948. However, it 
does not apply to any tire that has been so altered so as to render 
impossible its use, or its repair for use, as motor vehicle equipment.
* * * * *

0
3. Section 571.110 is amended by adding to S3, in alphabetical order, 
new definitions of ``Light truck (LT) tire'' and ``Passenger car 
tire'', and revising S4.1 and S4.2.2.3, to read as follows:


Sec.  571.110  Standard No. 110; Tire selection and rims for motor 
vehicles with a GVWR of 4,536 kilograms (10,000 pounds) or less.

* * * * *
    S3 Definitions.
* * * * *
    Light truck (LT) tire means a tire designated by its manufacturer 
as primarily intended for use on lightweight trucks or multipurpose 
passenger vehicles.
* * * * *
    Passenger car tire means a tire intended for use on passenger cars, 
multipurpose passenger vehicles, and trucks, that have a gross vehicle 
weight rating (GVWR) of 10,000 pounds or less.
* * * * *
    S4.1 General. Vehicles shall be equipped with tires that meet the 
requirements of Sec.  571.139, New pneumatic tires for light vehicles, 
except that passenger cars may be equipped with a pneumatic T-type 
temporary spare tire assembly that meets the requirements of Sec.  
571.109, or equipped with a non-pneumatic spare tire assembly that 
meets the requirements of Sec.  571.129, New non-pneumatic tires for 
passenger cars, and S6 and S8 of this standard. Passenger cars equipped 
with a non-pneumatic spare tire assembly shall meet the requirements of 
S4.3(e), and S5, and S7 of this standard.
* * * * *
    S4.2.2.3 (a) For vehicles, except trailers with no designated 
seating positions, equipped with passenger car tires, the vehicle 
normal load on the tire shall be no greater than 94 percent of the 
derated load rating at the vehicle manufacturer's recommended cold 
inflation pressure for that tire.
    (b) For vehicles, except trailers with no designated seating 
positions, equipped with LT tires, the vehicle normal load on the tire 
shall be no greater than 94 percent of the load rating at the vehicle 
manufacturer's recommended cold inflation pressure for that tire.
* * * * *

0
4. Section 571.119 is amended by revising Tables II and III to read as 
follows:


Sec.  571.119  Standard No. 119; New pneumatic tires for motor vehicles 
with a GVWR of more than 4,536 kilograms (10,000 pounds) and 
motorcycles.

* * * * *

[[Page 49211]]



                                                                            Table II.--Minimum Static Breaking Energy
                                                                             [Joules (J) and Inch-Pounds (inch-lbs)]
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                                                                                                                             Tires other than Light Truck, Motorcycle, 12 rim diameter code or
                                                                                         All 12 rim      Light truck and                                  smaller
                                                                                      diameter code or      17.5 rim     -----------------------------------------------------------------------
                        Tire characteristic                            Motorcycle      smaller except   diameter code or                    Tubeless greater                    Tubeless greater
                                                                                         motorcycle     smaller Tubeless      Tube type       than 17.5 rim       Tube type       than 17.5 rim
                                                                                                                                              diameter code                       diameter code
 
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------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 
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                 Plunger diameter (mm and inches)                   7.94 mm    \5/     19.05   \3/4\''   19.05   \3/4\''   31.75     1\1/    31.75     1\1/    38.10     1\1/    38.10     1\1/
                                                                              16\''      mm                mm                mm      4\''      mm      4\''      mm      2\''      mm      2\''
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                          Breaking Energy                              J      In-lbs     J      In-lbs     J      In-lbs     J      In-lbs     J      In-lbs     J      In-lbs     J      In-lbs
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Load Range:
    A.............................................................       16      150       67      600      225    2,000  .......  .......  .......  .......  .......  .......  .......  .......
    B.............................................................       33      300      135    1,200      293    2,600  .......  .......  .......  .......  .......  .......  .......  .......
    C.............................................................       45      400      203    1,800      361    3,200      768    6,800      576    5,100  .......  .......  .......  .......
    D.............................................................  .......  .......      271    2,400      514    4,550      892    7,900      734    6,500  .......  .......  .......  .......
    E.............................................................  .......  .......      338    3,000      576    5,100    1,412   12,500      971    8,600  .......  .......  .......  .......
    F.............................................................  .......  .......      406    3,600      644    5,700    1,785   15,800    1,412   12,500  .......  .......  .......  .......
    G.............................................................  .......  .......  .......  .......      711    6,300  .......  .......  .......  .......    2,282   20,200    1,694   15,000
    H.............................................................  .......  .......  .......  .......      768    6,800  .......  .......  .......  .......    2,598   23,000    2,090   18,500
    J.............................................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......    2,824   25,000    2,203   19,500
    L.............................................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......    3,050   27,000  .......  .......
    M.............................................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......    3,220   28,500  .......  .......
    N.............................................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......    3,389   30,000  .......  .......
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                                                           Table III.--Endurance Test Schedule
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                                                                            Test wheel       Test load: Percent of maximum load rating
                                                                               speed     ------------------------------------------------   Total test
                Description                          Load range          ----------------                                                   revolutions
                                                                           km/h     r/m      I-7 hours      II-16 hours    III-24 hours     (thousands)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Speed restricted service:
    90 km/h (55 mph)......................  F, G, H, J, L, M, N.........      40     125              66              84             101           352.0
    80 km/h (50 mph)......................  F, G, H, J, L...............      32     100              66              84             101           282.5
    56 km/h (35 mph)......................  All.........................      24      75              66              84             101           211.0
Motorcycle................................  All.........................      80     250         \1\ 100         \2\ 108             117           510.0
All other.................................  F...........................      64     200              66              84             101           564.0
                                            G...........................      56     175              66              84             101           493.5
                                            H, J, L, N..................      48     150              66              84             101           423.5
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* * * * *

0
5. Section 571.139 is amended by revising S2.1; S3; S5.2(c); S5.5; 
S5.5.4; S6.1.1.1.5; S6.1.2; S6.2.1.1.2; S6.4.1.1.2; and S6.6 to read as 
follows:


Sec.  571.139  Standard No. 139; New pneumatic radial tires for light 
vehicles.

* * * * *
    S2.1 Application. This standard applies to new pneumatic radial 
tires for use on motor vehicles (other than motorcycles and low speed 
vehicles) that have a gross vehicle weight rating (GVWR) of 10,000 
pounds or less and that were manufactured after 1975. This standard 
does not apply to special tires (ST) for trailers in highway service, 
tires for use on farm implements (FI) in agricultural service with 
intermittent highway use, tires with rim diameters of 8 inches and 
below, or T-type temporary use spare tires with radial construction.
* * * * *
    S3 Definitions.
    Bead means the part of the tire that is made of steel wires, 
wrapped or reinforced by ply cords and that is shaped to fit the rim.
    Bead separation means a breakdown of the bond between components in 
the bead.
    Bias ply tire means a pneumatic tire in which the ply cords that 
extend to the beads are laid at alternate angles substantially less 
than 90 degrees to the centerline of the tread.
    Carcass means the tire structure, except tread and sidewall rubber 
which, when inflated, bears the load.
    Chunking means the breaking away of pieces of the tread or 
sidewall.
    Cord means the strands forming the plies in the tire.
    Cord separation means the parting of cords from adjacent rubber 
compounds.
    Cracking means any parting within the tread, sidewall, or inner 
liner of the tire extending to cord material.
    Extra load tire means a tire designed to operate at higher loads 
and higher inflation pressure than the corresponding standard tire.
    Groove means the space between two adjacent tread ribs.
    Innerliner means the layer(s) forming the inside surface of a 
tubeless tire that contains the inflating medium within the tire.
    Innerliner separation means the parting of the innerliner from cord 
material in the carcass.
    Light truck (LT) tire means a tire designated by its manufacturer 
as primarily intended for use on lightweight trucks or multipurpose 
passenger vehicles.
    Load rating means the maximum load that a tire is rated to carry 
for a given inflation pressure.
    Maximum load rating means the load rating for a tire at the maximum 
permissible inflation pressure for that tire.
    Maximum permissible inflation pressure means the maximum cold 
inflation pressure to which a tire may be inflated.
    Measuring rim means the rim on which a tire is fitted for physical 
dimension requirements.
    Open splice means any parting at any junction of tread, sidewall, 
or innerliner that extends to cord material.
    Outer diameter means the overall diameter of an inflated new tire.

[[Page 49212]]

    Overall width means the linear distance between the exteriors of 
the sidewalls of an inflated tire, including elevations due to 
labeling, decorations, or protective bands or ribs.
    Passenger car tire means a tire intended for use on passenger cars, 
multipurpose passenger vehicles, and trucks, that have a gross vehicle 
weight rating (GVWR) of 10,000 pounds or less.
    Ply means a layer of rubber-coated parallel cords.
    Ply separation means a parting of rubber compound between adjacent 
plies.
    Pneumatic tire means a mechanical device made of rubber, chemicals, 
fabric and steel or other materials, that, when mounted on an 
automotive wheel, provides the traction and contains the gas or fluid 
that sustains the load.
    Radial ply tire means a pneumatic tire in which the ply cords that 
extend to the beads are laid at substantially 90 degrees to the 
centerline of the tread.
    Reinforced tire means a tire designed to operate at higher loads 
and at higher inflation pressures than the corresponding standard tire.
    Rim means a metal support for a tire or a tire and tube assembly 
upon which the tire beads are seated.
    Section width means the linear distance between the exteriors of 
the sidewalls of an inflated tire, excluding elevations due to 
labeling, decoration, or protective bands.
    Sidewall means that portion of a tire between the tread and bead.
    Sidewall separation means the parting of the rubber compound from 
the cord material in the sidewall.
    Test rim means the rim on which a tire is fitted for testing, and 
may be any rim listed as appropriate for use with that tire.
    Tread means that portion of a tire that comes into contact with the 
road.
    Tread rib means a tread section running circumferentially around a 
tire.
    Tread separation means pulling away of the tread from the tire 
carcass.
    Treadwear indicators (TWI) means the projections within the 
principal grooves designed to give a visual indication of the degrees 
of wear of the tread.
    Wheel-holding fixture means the fixture used to hold the wheel and 
tire assembly securely during testing.
* * * * *
    S5.2 Performance requirements. Each tire shall conform to each of 
the following:
* * * * *
    (c) Its maximum permissible inflation pressure shall be 240, 280, 
300, 340, or 350 kPa.
* * * * *
    S5.5 Tire markings. Except as specified in paragraphs (a) through 
(i) of S5.5, each tire must be marked on each sidewall with the 
information specified in S5.5(a) through (d) and on one sidewall with 
the information specified in S5.5(e) through (i) according to the 
phase-in schedule specified in S7 of this standard. The markings must 
be placed between the maximum section width and the bead on at least 
one sidewall, unless the maximum section width of the tire is located 
in an area that is not more than one-fourth of the distance from the 
bead to the shoulder of the tire. If the maximum section width falls 
within that area, those markings must appear between the bead and a 
point one-half the distance from the bead to the shoulder of the tire, 
on at least one sidewall. The markings must be in letters and numerals 
not less than 0.078 inches high and raised above or sunk below the tire 
surface not less than 0.015 inches.
* * * * *
    S5.5.4 For passenger car tires, if the maximum inflation pressure 
of a tire is 240, 280, 300, 340, or 350 kPa, then:
    (a) Each marking of that inflation pressure pursuant to S5.5(c) 
must be followed in parenthesis by the equivalent psi, rounded to the 
next higher whole number; and
    (b) Each marking of the tire's maximum load rating pursuant to 
S5.5(d) in kilograms must be followed in parenthesis by the equivalent 
load rating in pounds, rounded to the nearest whole number.
* * * * *
    S6.1.1.1.5 Readjust the tire pressure to that specified in 
S6.1.1.1.2.
* * * * *
    S6.1.2 Performance Requirements. The actual section width and 
overall width for each tire measured in accordance with S6.1.1.2 shall 
not exceed the section width specified in a submission made by an 
individual manufacturer, pursuant to S4.1.1(a) or in one of the 
publications described in S4.1.1(b) for its size designation and type 
by more than:
    (a) (For tires with a maximum permissible inflation pressure of 32, 
36, or 40 psi) 7 percent, or
    (b) (For tires with a maximum permissible inflation pressure of 
240, 280, 300, 340 or 350 kPa) 7 percent or 10 mm (0.4 inches), 
whichever is larger.
* * * * *
    S6.2.1.1.2 Condition the assembly at 32 to 38 [deg]C for not less 
than 3 hours.
* * * * *
    S6.4.1.1.2 After the tire is deflated to the appropriate test 
pressure in S6.4.1.1.1 at the completion of the endurance test, 
condition the assembly at 32 to 38 [deg]C for not less than 2 hours.
* * * * *
    S6.6 Tubeless tire bead unseating resistance. Each tire shall 
comply with the requirements of S5.2 of Sec.  571.109. For light truck 
tires, the maximum permissible inflation pressure to be used for the 
bead unseating test is as follows:

Load Range C...............................  260 kPa.
Load Range D...............................  340 kPa.
Load Range E...............................  410 kPa.
 

    For light truck tires with a nominal cross section greater than 295 
mm (11.5 inches), the maximum permissible inflation pressure to be used 
for the bead unseating test is as follows:

Load Range C...............................  190 kPa.
Load Range D...............................  260 kPa.
Load Range E...............................  340 kPa.
 

* * * * *

    Issued: August 22, 2007.
Stephen R. Kratzke,
Associate Administrator for Rulemaking.
 [FR Doc. E7-16934 Filed 8-27-07; 8:45 am]
BILLING CODE 4910-59-P