Consumer Information Regulations Uniform Tire Quality Grading Standards |
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Topics: National Highway Traffic Safety Administration
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Barry Felrice
Federal Register
April 25, 1994
[Federal Register: April 25, 1994] ======================================================================= ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION National Highway Traffic Safety Administration 49 CFR Part 575 [Docket No. 94-30, Notice 01] RIN 2127-AF17 Consumer Information Regulations Uniform Tire Quality Grading Standards AGENCY: National Highway Traffic Safety Administration (NHTSA), Department of Transportation (DOT). ACTION: Request for comments. ----------------------------------------------------------------------- SUMMARY: The Uniform Tire Quality Grading Standards (UTQGS) require tire manufacturers to grade their tires for treadwear, traction, and temperature resistance to assist consumers in making informed decisions when purchasing passenger car tires. NHTSA is soliciting comments on ways in which the agency might propose amending the UTQGS to make the quality ratings more meaningful to the tire-buying public. In addition, the Administration's Climate Change Action Plan calls for DOT, through NHTSA, to establish tire labels measuring the tires' impact on fuel economy due to rolling resistance and an information program to encourage consumers to purchase aftermarket tires with lower rolling resistance. Accordingly, NHTSA requests comments on whether to propose amending the UTQGS by adding a rolling resistance grade, either while retaining the temperature resistance grade or by substituting the rolling resistance for the temperature resistance grade. DATES: Comments must be received by June 24, 1994. ADDRESSES: Comments should refer to the docket and notice number set forth above and be submitted, preferably in 10 copies, to: Docket Section, National Highway Traffic Safety Administration, 400 Seventh Street SW., room 5109, Washington, DC 20590. Docket room hours are from 9:30 a.m. to 4 p.m., Monday through Friday. FOR FURTHER INFORMATION CONTACT: Mr. Nelson Gordy, Office of Market Incentives, Office of the Associate Administrator for Rulemaking, National Highway Traffic Safety Administration, 400 Seventh Street SW., room 5320, Washington, DC 20590, (202) 366-4797. SUPPLEMENTARY INFORMATION: Section 203 of the National Traffic and Motor Vehicle Safety Act of 1966, 15 U.S.C. 1381, et seq. (Safety Act), requires the Secretary of Transportation to prescribe a uniform quality grading system for motor vehicle tires. The purpose of the system is to assist consumers in making informed decisions when purchasing tires. NHTSA implemented that statutory mandate by issuing the UTQGS (49 CFR 575.104). Those standards, applicable to passenger car tires, require motor vehicle and tire manufacturers and tire brand name owners to provide consumers with information about their tires' relative performance regarding treadwear, traction, and temperature resistance. Excluded from the standards are deep tread, winter-type snow tires, space-saver or temporary use spare tires, tires with nominal rim diameters of 10 to 12 inches, and limited production tires. The treadwear, traction, and temperature resistance characteristics were chosen by NHTSA for rating under the UTQGS after careful study, testing, and consideration of public comments. Those characteristics were selected because they provide the best balance of tire properties for meaningful evaluation by consumers. Those characteristics interact with each other so that improvement of one of them could detract from the rating of another. For example, treadwear life can be increased by varying the construction compounds to produce a ``harder'' tire. To do so, however, would have a negative effect on traction performance. Treadwear life could also be increased by adding more rubber to the tread. Increased tread depth, however, would increase rolling resistance because of the additional friction. That would cause the tire to run hotter, thus detracting from its temperature resistance, and increase the possibility of tire failure. Various problems have been encountered in implementing the UTQGS to make them as technically accurate, yet as meaningful and understandable to consumers as possible. Many of those problems have been resolved by changes in test procedures as the program has evolved. Certain problems remain, however, as discussed below. I. Treadwear Treadwear has been one of the graded tire characteristics from the inception of the quality grading program (see 33 FR 7261, May 16, 1968). NHTSA concluded, from consideration of public comments early in the program, that consumers were most interested in evaluations of tire tread life, traction, and high speed performance. Since that time, NHTSA has found that treadwear is understood by the average tire buyer, making it one of the more meaningful of the UTQGS ratings. In its compliance testing, NHTSA measures treadwear by running the tires being tested, called candidate tires, over a 400-mile course of public roads near San Angelo, Texas. Candidate tires are first ``broken-in'' by running them over two circuits of the test course. Treadwear measurements are taken after that initial break-in and after each 800-mile segment thereafter or, optionally, only at the beginning and at the end of the complete 6,400 mile test. The test vehicles' wheels are aligned to manufacturers' specifications, correct tire pressure is maintained throughout the test, and tire loading is maintained at 85 percent of the tires' maximum load ratings. The test cars travel in convoys, at posted speed limits, with regular changes of drivers and with changes in the positions of the cars and tires. Upon completion of the 6,400-mile test, the adjusted wear rate for a candidate tire is extrapolated to the point of wearout, which is \1/ 16\th inch of tread remaining, and the treadwear grade established. A grade of 100 represents a tire capable of achieving approximately 30,000 miles to the wearout point, as measured on the San Angelo course. A tire graded at 150 should achieve approximately 50 percent more mileage than the one graded at 100, assuming both are run on the same course and under the same conditions. It should be noted, however, that tire treadwear grades are not intended to be indicative of a tire's actual expected mileage. The tire quality grades are intended as indicators of relative, not absolute, performance. The actual mileage a tire achieves will depend on many factors, such as geographic location, individual driving habits, maintenance of proper tire pressure, load, type of road surfaces, climatic conditions, and road configurations. NHTSA has noted significant changes in treadwear ratings since the UTQGS became fully effective in 1980. Early in the UTQGS program, the treadwear grading criteria specified in Sec. 575.104(d)(2) produced consistent results. As the years progressed, however, treadwear ratings have drifted steadily upward in both manufacturers' and NHTSA's testing results to the point that many of the ratings appear to be questionable. For example, one brand of tires (brand A) recently tested on the San Angelo course resulted in a test grade of 832 which, when rounded off to the next lower 20-point increment as required by 49 CFR 575.104(e)(2)(ix)(F), would be labeled with a treadwear grade of 820. That figure suggests a degree of relative superiority in treadwear of brand A tires over lower tested brands that appears significantly disproportionate to the differences in the likely actual mileage of those tires. NHTSA understands that tires are of higher quality, perform better and last longer than tires produced even a few years ago. Such improvements result from industry developments such as improvements in rubber compounds, cord materials, tire designs, and tread configurations. The agency does not believe, however, that tires have improved to the point suggested by the test results for brand A, which suggests that, on the San Angelo course, the tire would last over 240,000 miles. This situation suggests either that the characteristics of the course itself are changing or that other factors as yet unidentified are responsible, or both. Course Monitoring Tires As noted above, the wear rates of tires can change on a daily basis because of such conditions as road surface, temperature, humidity, and precipitation. To compensate for those changes in conditions when conducting agency compliance testing, candidate tires are tested concurrently with course monitoring tires (CMT). Before 1991, CMTs were built to strict NHTSA specifications. Since that time, NHTSA has required that CMTs be built to the specifications of the American Society for Testing Materials (ASTM) standard E1136. CMTs are specially designed to have narrow limits of variability and, in fact, are assumed to be invariant among tires of a given batch, or lot. CMTs are procured by NHTSA in lots of 500-1500. Whenever a new lot is procured, a new base course wear rate (BCWR) is established for that lot. This is accomplished by treating the new CMT as a candidate tire and determining its adjusted wear rate in the same manner prescribed in Sec. 575.104 for candidate tires. The new CMT is tested in a convoy along with the old CMTs. A course severity adjustment factor (CSAF) is determined by dividing the BCWR for the old CMTs by the wear rate of the old CMTs in the test. The wear rate of the new CMT in the convoy is then multiplied by the CSAF to obtain the adjusted wear rate of the new CMT which then becomes the BCWR for the new CMTs. Once the BCWR for a new lot of CMTs is established, those new CMTs can then be used to grade candidate tires. Upon completion of the 6,400-mile test, the BCWR is divided by the average wear rate of the 4 new CMTs in the test convoy to determine the course severity adjustment factor. That factor is then applied to the wear rates of the candidate tires being graded in the same convoy. The adjusted wear rate of the candidate tire is then extrapolated to the point of wearout (\1/16\th inch tread remaining) which is then converted to the treadwear rating for that tire. NHTSA has noted over the years that significant changes have occurred in the BCWRs. Although the actual measured treadwear rates of CMTs have varied from 3.27 to 6.96 mils per 1,000 miles since 1975, the adjusted BCWRs have steadily decreased from 4.44 in 1975 to 1.56 in 1992, as shown in Table 1, as follows: Table 1.--CMT Wear Rates and Base Course Wear Rate Adjustment Factors ---------------------------------------------------------------------------------------------------------------- Wear rate (mils per Year tested Manufacturer Series 1,000 BCWR miles) ---------------------------------------------------------------------------------------------------------------- 1975........................... Goodyear........................... Batch 1......... 4.44 4.44 1979........................... Goodyear........................... Batch 1......... 4.08 1979........................... Goodyear........................... Batch 2......... 3.82 4.16 1980........................... Goodyear........................... Batch 2......... 5.29 1980........................... Goodyear........................... Batch 3......... 4.76 3.74 1984........................... Goodyear........................... Batch 3......... 4.22 1984........................... Uniroyal........................... 40000........... 3.27 2.89 1987........................... Uniroyal........................... 40000........... 5.96 1987........................... Uniroyal........................... 71000........... 4.56 2.21 1989........................... Uniroyal........................... 71000........... 5.01 1989........................... Uniroyal........................... 91000........... 4.84 2.14 1991........................... Uniroyal........................... 91000........... 6.24 1991........................... ASTM E1136......................... 010000.......... 4.94 1.70 1991........................... ASTM E1136......................... 010000.......... 6.96 1992........................... ASTM E1136......................... 110000.......... 6.65 1.62 1992........................... ASTM E1136......................... 110000.......... 5.83 1992........................... ASTM E1136......................... 210000.......... 5.60 1.56 1993........................... ASTM E1136......................... 210000.......... 7.21 1993........................... ASTM E1136......................... 310000.......... 6.80 1.47 ---------------------------------------------------------------------------------------------------------------- The BCWR and the actual wear rate theoretically should correlate reasonably well. Any differences may be due to climatic variations, changes in course severity, non-uniformity of wear rates between individual tires within the same lot, effects of aging and storage on the wear rates of the CMTs, errors in the calculation for adjusting BCWRs, or perhaps some combination of those factors. The test course is well maintained by the State of Texas and does not appear to have changed appreciably since testing first started there in 1975. That suggests that a significant part of the change in BCWRs may be attributed to the CMTs instead of course variability. NHTSA has noted that in every case in which one lot of CMTs is replaced by another, the new lot invariably shows a lower BCWR than the former. The first batch of CMTs were procured from Goodyear Tire and Rubber Company in 1975 and had a wear rate of 4.44. Tires from that same lot were tested again in 1979 and showed a wear rate of 4.08. A new CMT batch was purchased in 1979 which showed a wear rate of 3.82. By 1980, however, tires tested from that batch showed an increased wear rate of 5.29. In each batch, the wear rate varied when tested at a later date, from one to four years after purchase. A possible explanation for those changes in wear rate among tires in the same lot could be attributed to aging and/or environmental degradation of the tires. To minimize those factors, the agency now purchases a one-year supply of CMTs at a time and stores them in the basement area of a warehouse which is typically 20 degrees cooler than ambient summer temperature. In addition to the aging/environmental degradation of CMTs affecting the BCWR, the agency believes that the method of calculating the BCWR may be in error. As stated above, the purpose of using a CMT is to provide a common baseline for all candidate tires. However, it appears that the practice of relating all new CMTs to all prior CMTs by the procedure described above has somehow distorted the treadwear grading procedure to the point that treadwear grades of candidate tires are now highly suspect. If, instead of utilizing the BCWR to establish treadwear grades, the wear rates of the CMTs were compared directly to those of the candidate tires to determine the projected mileage of the candidate tires, much lower and perhaps more realistic grades would result. In the case of the previous example, the average wear rate for these candidate tires was 4.90 mils per 1,000 miles when tested. For the CMTs that accompanied these tires, with the same convoy, the average wear rate was 6.49 mils per 1,000 miles. The actual wearout rate for radial CMTs tested in 1975 was 67,000 miles, which is equivalent to a grade of 223. By assuming that the wearout for the CMTs remains the same, the calculated wearout for the tires in question would be 88,700 miles (6.49/4.90 x 67,000). This would be equivalent to a grade of 295 or 280 when rounded off to the nearest lower 20-point increment. The direct comparison of wear rates between CMTs and candidate tires may produce lower and more realistic grades for tires. It would, however, change the original intent of the CMT, which was to provide a common baseline for comparison, regardless of when a candidate tire is tested. Further, it would present a problem for the marketing of tires that are already graded and still in production. Nevertheless, improvement in the treadwear grading procedure appears to be needed in order to provide treadwear grades that are realistic, consistent, and meaningful to consumers. II. Traction Traction grades are established on test pads also located at San Angelo, Texas. Two surfaces are used in the test: wet asphalt and wet concrete. A test trailer is equipped with ASTM E501 standard tires utilized in the tests as control tires. Two standard tires are inflated to 24 pounds per square inch (psi), statically balanced, allowed to cool to ambient temperature (with inflation pressure readjusted as necessary), and mounted on the test trailer. Each tire is then loaded to 1,085 pounds. The trailer is towed by a light truck over the wet asphalt surface at a speed of 40 miles per hour (mph). One wheel is locked, and the locked-wheel traction coefficient is recorded for that wheel for a period of 0.5 to 1.5 seconds after lockup. The test is then repeated on the wet concrete surface, locking the same wheel. Those procedures are repeated 10 times on each surface for each wheel. The 20 measurements taken on each surface are averaged to find the standard traction coefficient for each surface. Those standard traction coefficients are then utilized to determine the adjusted traction coefficients of the candidate tires. Two candidate tires of the same construction type, manufacturer, line, and size designation are prepared and tested utilizing the same test procedures described above for the standard tires, except that the candidate tires are loaded to 85 percent of the test loads specified in Sec. 575.104(h). The adjusted traction coefficients of the candidate tires are determined in accordance with Sec. 575.104(f)(2) (ix) and (x). Once tested, candidate tires are assigned grades ``A'', ``B'', or ``C''. A tire that achieved a high level of performance on both asphalt (above 0.47) and concrete (above 0.35 ) is graded ``A''. A tire achieving at least medium performance on both surfaces is graded ``B'' (above 0.38 on asphalt and above 0.26 on concrete). A tire achieving relatively low performance on either or both surfaces (below 0.38 on asphalt or below 0.26 on concrete) is graded ``C''. From examining traction test data, NHTSA has observed that while nearly all tires achieve high traction values on the wet asphalt surface, very few achieve high values on the wet concrete surface. NHTSA conducted a statistical analysis of the traction test data since 1989 to determine the frequency distribution of the traction coefficients of tires tested on both surfaces. The analysis showed that the arithmetic mean of the traction coefficients of tires on the wet asphalt surface was 0.51 , and the standard deviation was 0.03 . Assuming a normal distribution (in a normal or bell-shaped distribution, one standard deviation on both sides of the arithmetic mean represents 68.27% of the values included within the limits indicated (see ``Statistical Methods,'' by Arkin and Colton, 4th Ed. (Rev.), 1958, pages 37 and 38)), it follows that approximately 68 percent of the tires tested on the asphalt surface would have a traction coefficient greater than 0.48 , but less than 0.54 . The arithmetic mean of traction coefficients of tires tested on the wet concrete surface was 0.38 , 0.03 , indicating that approximately 68 percent of the tires tested on the wet concrete surface would have a traction coefficient greater than 0.35 , but less than 0.41 . That analysis suggests that tire traction has improved to the point that it may be appropriate to upgrade the standard by raising the minimum traction values for each category. For example, an ``A'' rating could call for a traction coefficient above 0.54 on asphalt and above 0.41 on concrete; a ``B'' rating could be above 0.48 on asphalt and above 0.35 on concrete; and for ``C'', below 0.48 on asphalt and below 0.35 on concrete. Alternatively, a new category ``AA'' could be created, the lower limit of which could be 0.54 for asphalt and 0.41 for concrete, with the ``A'', ``B'', and ``C'' categories remaining as they are. Either of these alternatives would result in a more balanced distribution of tires among grades ``A'', ``B'', and ``C''. Another area of increasing concern in traction testing is the possible use of a peak tire traction category for testing rather than the sliding traction presently measured. Contemporary vehicles are increasingly utilizing anti-lock brakes where sliding traction is not the primary traction force in panic braking. Those vehicles rely on peak tire traction, that is, maximum braking action is obtained when the tire is still rolling. Although peak tire traction may be desirable information for consumers with vehicles equipped with anti-lock brakes, high peak traction may compromise other tire characteristics such as degradation of traction when cornering. If peak traction performance of tires differs substantially from sliding traction, an alternative traction grading procedure may be necessary. NHTSA needs additional data on the measurement of peak traction coefficients and on the correlation of peak traction coefficients with stopping distance, which may be available from commenters. The agency is soliciting any such data. III. Temperature Resistance The temperature resistance grade is intended to indicate the extent to which heat is generated and/or dissipated by a given tire, and the capability of the tire to withstand the resulting temperature without failure. The heat that is generated depends on the amount of energy absorbed by the tire in the flexing of the rubber and its reinforcing materials. That energy is wasted and appears in the tire as heat. The more energy wasted, the greater the amount of heat that is generated and, if the tire is not capable of dissipating that greater amount of heat and/or if the tire is not able to resist the effects of the higher operating temperature that results from that greater amount of heat, the lower the temperature resistance grade. Heat buildup in tires is generally caused by vehicle overloading, high speed operation, and/or tire underinflation. Sustained high temperature can cause structural degeneration of the material of the tire and result in reduced tire life or potential catastrophic tire failure. A tire's resistance to temperature buildup is graded under the UTQGS as ``A'', ``B'', or ``C'', with ``A'' being the best and ``C'' being the minimum standard of performance. Tires of high quality, as a result of superior design and construction, can be expected to last longer without failure when subjected to sustained high speed operation. NHTSA tests tires for temperature resistance using the same laboratory test wheel utilized in testing a tire's high speed performance under Federal Motor Vehicle Safety Standard (FMVSS) No. 109, New Pneumatic Tires. The high speed performance test under FMVSS 109 is run at speeds of up to 85 mph. The temperature resistance test under the UTQGS, however, is run at speeds of up to 115 mph. A tire graded ``A'' has successfully completed the test procedure at a sustained speed of 115 mph on the test wheel. A grade of ``B'' means that the tire has successfully completed the test procedure at speeds between 100 mph and 115 mph; and a ``C'' grade indicates satisfactory completion of the test at speeds exceeding 85 mph but at or below 100 mph. Of the 2,100 tires graded in 1993, 30 percent were graded ``C'', 50 percent were graded ``B'', and 20 percent were graded ``A''. NHTSA considers temperature resistance a valid safety concern and is unaware of any problems with the ratings. While important from a motor vehicle safety standpoint, however, the significance of temperature resistance is not so widely understood by consumers as the treadwear and traction ratings. In light of this fact, and recent interest in a rolling resistance grade, the agency is considering whether a rolling resistance grade could provide equivalent safety information to the temperature resistance grade and thereby negate the need for temperature resistance grading. The issue of a rolling resistance grade arose at the White House Conference on Global Climate Change on June 10 and 11, 1993. At the White House Conference, a number of measures to reduce greenhouse gasses were discussed. One of the many measures related to vehicle fuel economy was the increased use of low rolling resistance tires in the aftermarket. Michelin presented a paper on that issue at a meeting of the Auto and Light Truck Workshop of the Transportation Working Group of the White House Conference on Global Climate Change on July 1, 1993. Michelin asserted that the average rolling resistance for all-season radial original equipment manufacturer (OEM) tires was 22.6 percent less than that for all-season radial replacement tires. Further, if replacement tires had the same rolling resistance as OEM tires, a 4 percent overall improvement in fuel economy could be realized. Finally, Michelin announced a manufacturing process by which low rolling resistance tires could be produced with no increase in inflation pressures. As a result of the conference, the Administration issued a report on a series of initiatives to reduce greenhouse gas emissions, entitled The Climate Change Action Plan, on October 19, 1993. Among other things, the Plan calls for reduction of U.S. greenhouse gas emissions to 1990 levels by the year 2000. The Plan contains nearly 50 initiatives to accomplish that goal. One of those initiatives calls for DOT, through NHTSA, to issue new rules and test procedures requiring tire manufacturers to test and label tires relative to their rolling resistance. This request for comments is part of NHTSA's commitment to The Climate Change Action Plan. Because the UTQGS are not applicable to truck tires, NHTSA's Office of Research and Development will, in a separate but related action, work with truck tire manufacturers and truck fleet and owner organizations to promote a voluntary truck tire rolling resistance program. The agency also notes that one of the factors that causes heat generation in tires also causes higher rolling resistance. Indeed, the friction resulting from a tire's rolling resistance is the immediate cause of heat generation in the tire. Rolling resistance is measured in a procedure similar to that used for determining temperature resistance. The rolling resistance test consists of running a tire under load on a laboratory test wheel. The energy consumed in and recovered from running the tire is measured and the difference is the heat energy lost which is a measure of rolling resistance. The smaller the difference, the more fuel efficient the tire. Since rolling resistance and temperature resistance are related and are measured by similar tests, it is necessary to determine whether any safety benefits would be lost by substituting rolling resistance for temperature resistance in the UTQGS. FMVSS No. 109 would continue to ensure that all tires are capable of operating safely at speeds up to 85 mph, thereby establishing a minimum safety threshold. Further, fuel efficiency could be expected to generate more interest and be more easily understood by consumers than temperature resistance, thereby enhancing the usefulness of the UTQGS to the consumers it is intended to assist. However, the agency requests comments on this issue. NHTSA believes that there is a strong relationship between rolling resistance and fuel consumption. Rolling resistance data generated under existing SAE test procedures could be used for quantifying the correlation with fuel consumption. SAE Recommended Practices J1269 and J1270 specify rolling resistance measurement procedures for passenger car tires. The agency would welcome data that could be used to demonstrate how reductions in tire rolling resistance values translate into improvements in ``real world'' fuel economy. IV. Issues for NHTSA Evaluation As stated above, the objective of the UTQGS is to provide meaningful, comparative information to consumers that will assist them in making informed selections when purchasing passenger car tires. In addition, the UTQGS should stimulate competitive forces in the marketplace, resulting in better tire performance. By improving the UTQGS, NHTSA believes it can achieve those goals. The agency is hopeful, therefore, that this notice will elicit useful comments and suggestions on the UTQGS issues discussed above. NHTSA's major concerns are whether to propose changes to deal with treadwear grades that are becoming extremely high and therefore of diminishing credibility; whether to propose raising the thresholds for traction grades; and whether it is more appropriate under the National Traffic and Motor Vehicle Safety Act for the agency to propose adding rolling resistance to the UTQGS as a fourth grading category or substituting it for temperature resistance. NHTSA specifically requests comments on the following issues: 1. Does the existing system for measuring treadwear result in misleading grades? Why? 2. Should a new system be developed for establishing treadwear grades? What system? 3. Should the treadwear test procedure be changed? What specific changes should be made? Why? What data are available to support such changes? How should such changes be implemented? 4. Should the test course calibration procedure be changed? What changes should be made? 5. How should traction grades be determined or improved? Does traction change significantly with wear for any tire lines? 6. Should the traction grades be upgraded? By raising the minimum values for each category (A, B, C)? By creating a new category, such as ``AA''? By other means? 7. Should the UTQGS include peak tire traction ratings? Does peak tire traction correlate with stopping distance on ABS-equipped vehicles? Can the peak tire traction coefficient be measured reliably? How could/should it be expressed? 8. What would be the cost of measuring peak traction? In addition to sliding traction? Instead of sliding traction? 9. Are the characteristics related to a tire's ability to dissipate heat and to withstand higher operating temperatures that affect a tire's temperature resistance rating directly related to a tire's rolling resistance? 10. Should the temperature resistance grade be deleted from the UTQGS? Is it adequately represented by the voluntary tire industry speed ratings? 11. Should a rolling resistance grade replace temperature resistance? How would such a grade be expressed? How would it be labeled on the tire? 12. Should a rolling resistance grade be added to the UTQGS as a fourth category? 13. How would the agency explain to consumers the correlation between rolling resistance and fuel economy? 14. Can rolling resistance be improved without detracting from the other graded characteristics? What is the additional cost per tire? Do you agree with the costs projected in The Climate Change Action Plan? 15. Can tires of the same size, construction, and load carrying capacity which have the same rolling resistance, exhibit significantly different temperature resistance performance? 16. Would any safety values be affected if rolling resistance replaced temperature resistance? 17. How should data based on the test procedures of SAE-J1269 and SAE-J1270 be utilized to compare the rolling resistance performance of different tires? 18. What data regarding rolling resistance of different tire designs currently exist? 19. What is the range of rolling resistance performance available both to OEM and aftermarket passenger car tires today? What is the potential for further reductions in rolling resistance for tires of various types, such as all-season, mud/snow, rain, and conventional? 20. Are there improvements that should be made in the current procedures for measuring rolling resistance? If so, please describe how those measures could be improved, and at what additional cost. 21. What should be done about tires already graded? 22. What would be the most effective campaign to publicize the low rolling resistance/fuel efficiency program? 23. What procedures would be most effective in monitoring the low rolling resistance/fuel efficiency program to assure maximum results? 24. What is the estimated incremental consumer cost increase for low rolling resistance tires of various types? 25. What is the estimated cost effectiveness for low rolling resistance tires of various types? How cost effective would low rolling resistance tires have to be to motivate consumers to buy them? 26. What is the current cost of tire labeling for treadwear, traction, and temperature resistance combined on a per tire basis, assuming a high volume production line? How would this cost change if rolling resistance replaced temperature resistance? If it were added, without replacing any of the existing UTQGS requirements? 27. What are current equipment and per test costs to measure temperature resistance according to UTQGS? Rolling resistance according to SAE guidelines? 28. Is it necessary to replace all 4 tires to achieve the benefits of lower rolling resistance tires? What are the fuel savings if fewer than 4 tires are replaced? 29. What is the frequency with which consumers replace 4 tires at once? Three tires? Two tires? 30. Are there other or additional measures NHTSA should consider to aid in reducing greenhouse gasses? What are the costs and benefits of these measures? V. Rulemaking Analyses and Notices A. Executive Order 12866 (Regulatory Analysis and Review) and DOT Regulatory Policies and Procedures. This notice was not reviewed under E.O. 12866. NHTSA has considered the impacts associated with this request for comments and has concluded that it is not significant under DOT's Regulatory Policies and Procedures. As explained above, this document requests comments to aid the agency in determining whether to propose improvements in the UTQGS and whether to propose either adding a rolling resistance grade or substituting a rolling resistance grade for the currently-required temperature resistance grade. Improvements in the UTQGS would make them more meaningful and understandable to consumers and contribute to energy conservation in accordance with the President's Climate Change Action Plan. B. Executive Order 12612 (Federalism) NHTSA has analyzed this action under the principles and criteria of E.O. 12612. The agency has determined that this request for comments does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. VI. Comments Interested persons are invited to submit comments. It is requested, but not required, that comments be submitted in 10 copies. Comments must not exceed 15 pages in length (49 CFR 553.21). Necessary attachments may be appended to such submissions without regard to the 15-page limit. This limitation is intended to encourage commenters to state their primary arguments in a concise fashion. All comments are retained in the NHTSA Docket Section and are open and available to the public for review and copying. If a commenter wishes to submit certain information under a claim of confidentiality, 3 copies of the complete submission, including the business information for which confidentiality is requested, should be submitted to the Chief Counsel, NHTSA, at the address shown above. Seven copies from which the purportedly confidential business information has been deleted should be submitted to the NHTSA Docket Section. A request for confidentiality should be accompanied by a cover letter setting forth the information specified in 49 CFR part 512, Confidential Business Information. Those commenters desiring to be notified upon receipt of their comments in the NHTSA Docket Section should enclose a self-addressed stamped postcard in the envelope with their comment. Upon receipt of the comment in the Docket Section, the docket supervisor will return the postcard by mail. List of Subjects in 49 CFR Part 575 Consumer Information Regulations: Vehicle stopping distance, Truck- camper loading, Uniform tire quality grading standards, Utility vehicles. Issued on April 20, 1994. Barry Felrice, Associate Administrator for Rulemaking. [FR Doc. 94-9916 Filed 4-22-94; 8:45 am] BILLING CODE 4910-59-P