303:
between the wheel and the road surface, and deforms towards the rear of the vehicle. This generates a traction force to oppose the motion of the vehicle. As braking torque increases, the tire deforms more and tread elements near the rear of the contact patch with the road begin to slip rather than grip. The coefficient of friction rapidly reaches a maximum value at about 10-20 percent slip, and then declines as the longitudinal slip values increase to 100 percent, which represents a fully locked tire. The maximum coefficient of friction in the 0-100 percent slip range is termed "peak" coefficient of friction, and the lower coefficient value for the fully locked tire is termed "slide" coefficient of friction.
149:
means that a tire with a 200 grade will wear twice the distance as a tire with a 100 grade. However, tire manufacturers are not under any obligation to grade a tire based on the test results, except to say that they cannot overstate the grade. This is enforced by NHTSA requiring documentation to justify any assignment of a grade on a tire, "These treadwear grades are no guarantee of actual tire mileage; differences in driving habits, service practices, climate, and road characteristics will affect a tire's longevity."
106:(NHTSA) established the Uniform Tire Quality Grading Standards (UTQGS) in 49 CFR 575.104. When looking at UTQG ratings it is important to realize that the Department of Transportation does not conduct the tests. The grades are assigned by the tire manufacturers based on their test results or those conducted by an independent testing company they have hired. The NHTSA has the right to inspect tire manufacturers' data, and can fine them if inconsistencies are found.
33:
1231:
299:
The tow truck is equipped with an on-board water supply system that sprays water in front of the test tire. The brakes, from the test tire only, are momentarily locked, and sensors on the axle measure the longitudinal and vertical forces as it slides in a straight line. The coefficient of friction for the pair, test tire and surface, is then determined as the ratio of the longitudinal and vertical forces.
1221:
45:
91:(DOT). All passenger car tires manufactured for sale in the United States since March 31, 1979 are federally mandated to have the UTQG ratings on their sidewall as part of the DOT approval process, in which non-DOT approved tires are not legal for street use in the United States. Light truck tires are not required to have a UTQG. It is not to be confused with the
302:
The UTQGS traction rating procedure specifies that the traction coefficients for asphalt and for concrete are to be calculated using the locked-wheel traction coefficient on the tire, or sliding coefficient of friction. More specifically, upon application of the brakes, the tire is subjected to shear
148:
The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test track. A tire graded 200 would last twice the distance on the government test course under specified test conditions as one graded 100. In theory, this
294:
Traction grades, from highest to lowest, are AA, A, B and C. They represent the tire's ability to stop on wet pavement as measured under controlled conditions on specified government test surfaces of asphalt and concrete. The testing does not take into account cornering, hydroplaning, acceleration
266:
However, this is an average rule, and for the same friction coefficient, the curve in this study shows large variations in treadwear rating, which decrease the significance of this relationship. Thus, depending on production method and tire model, the quality of rubber (thanks to certain additives)
298:
The UTQGS traction test procedure measures a tire's coefficient of friction when it is tested on wet asphalt and concrete surfaces. The test tire is installed on an instrumented axle of a traction trailer, which is towed by a truck at 40 miles per hour (mph) over wet asphalt and concrete surfaces.
282:
It is legal and permissible for a tire manufacturer to give a particular tire line a lower treadwear grade. For example, if the highest treadwear grade in a manufacturer's lineup is 600, then a tire line with a lower treadwear test result might receive a grade of 400, instead of the 480 it could
373:
The temperature grades, from highest to lowest, are A, B and C. These represent the tire's resistance to the generation of heat at speed. Tires graded A effectively dissipate heat up to a maximum speed that is greater than 115 mph. B rates at a maximum between 100 mph and 115 mph. C rates at a
275:
The treadwear grade is a ratio and not a mileage. This is because multiple factors determine treadwear rates and most of them are a function of driving conditions and operating environment, and not the tire itself. As a result, actual tire wear will vary considerably within the same tire line.
152:
As Course
Monitoring Tires have changed, their treadwear grades have changed to numbers considerably higher than 100. As a result, it would be incorrect to say that a tire with a treadwear grade of 200 gets twice the life of the Course Monitoring Tire.
132:
Standard 109 requires the following to be listed on the tire's sidewall: speed restriction if less than 55 mph, regroovable if designed for regrooving, and a letter designating load range rating.
169:
during the test, thus ensuring that the candidate tires and the CMT tires experience the same road conditions. The convoy, typically comprising four or fewer vehicles, will drive 7200 miles on
279:
The assigning of UTQG grades is done solely by the tire manufacturer. In many cases, this has resulted in the UTQG grading system to be more of a marketing tool than was originally intended.
254:
161:
The wear on tires that are being tested ("candidate tires") is compared to the wear of Course
Monitoring Tires (CMT), which are sold by the NHTSA at its UTQG test facility in
295:
or stopping on a dry surface. Nor does it account for the significantly different effectiveness of ABS versus non-ABS braking systems on a tire's stopping distance.
286:
Also, it is common for tires whose treadwear grade is of little commercial value, such as racing tires, to be assigned extremely low values - sometimes even zero.
103:
96:
84:
95:, a supplemental and global standard measuring tire dimensions, load-bearing ability and maximum speed, maintained by tire industry trade organizations and the
1163:
393:
88:
1260:
510:
482:
112:
Dedicated winter tires, also known as snow tires, are not required to have a UTQG rating. Non-passenger car tires, such as those for
109:
The NHTSA published DOT HS 812 325 “Consumer Guide to
Uniform Tire Quality Grading” August 2016, which provides rating information.
177:. Candidate tire wear will be checked during and after the test, and compared to the wear on the CMT tires from the same convoy.
181:
1062:
658:
276:
However, two tires with exactly the same compound should have a treadwear rating that varies in accordance with tread depth.
1265:
1052:
37:
259:
Generally speaking, a lower treadwear rating correlates with a higher friction coefficient and thus provides a shorter
1270:
1173:
693:
214:
1275:
418:
574:
432:
208:(ÎĽ) and the treadwear rating of tires tested. This relationship can be represented by the following formula:
1014:
971:
901:
205:
374:
maximum of between 85 mph to 100 mph. Tires that cannot grade up to C or higher cannot be sold in the US.
1110:
981:
976:
80:
624:
961:
941:
1067:
703:
651:
76:
1220:
537:"An Evaluation of the Uniform Tire Quality Grading Standards and Other Tire Labeling Requirements"
1105:
936:
189:
599:
193:
184:
produced all CMT tires from 1975 until 1984. From 1984 to 1991, the CMT tires were produced by
32:
536:
931:
808:
162:
125:
267:
can multiply the treadwear rating by more than 3 without lessening the friction coefficient.
1224:
1183:
1155:
1097:
1037:
1029:
996:
986:
896:
883:
828:
818:
758:
748:
728:
675:
260:
966:
926:
916:
911:
851:
793:
263:. A softer, more sticky tire, wears off its material faster to provide this performance.
1255:
1234:
1145:
1135:
1125:
951:
871:
763:
644:
53:
1249:
1042:
1009:
906:
891:
738:
698:
683:
561:
140:
The UTQG rating is made up of three components, treadwear, traction and temperature.
44:
1168:
1082:
1077:
1047:
956:
866:
861:
803:
783:
778:
708:
388:
170:
457:
633:- U.S. Government service to look up treadwear grades on different type of tires.
1196:
1120:
1072:
1057:
1004:
773:
753:
743:
688:
1201:
1019:
946:
856:
846:
813:
398:
174:
113:
1191:
1140:
1130:
1087:
836:
798:
788:
723:
718:
383:
180:
The first CMTs were commercially-available
Goodyear Custom Steelguards, and
92:
49:
841:
733:
185:
165:. Both types of tires are mounted on vehicles that will be driven in a
1115:
921:
166:
17:
192:
standard E1136 to have particularly narrow limits of variability."
713:
129:
121:
43:
31:
204:
A study has shown a statistical relationship between the average
1206:
768:
667:
72:
68:
640:
117:
630:
458:"49 CFR 575.104 - Uniform tire quality grading standards"
636:
188:. CMT tires are now "specially designed and built to
128:
are also not required to have a UTQG rating, although
217:
1182:
1154:
1096:
1028:
995:
882:
827:
674:
419:"The Grand History and Evolution of UTQG – Part II"
248:
190:American Society for Testing and Materials (ASTM)
511:"Understanding the UTQG car tire-grading system"
483:"Consumer Guide to Uniform Tire Quality Grading"
249:{\displaystyle \mu ={\frac {2.25}{TW^{0.15}}}}
104:National Highway Traffic Safety Administration
97:International Organization for Standardization
85:National Highway Traffic Safety Administration
652:
8:
1164:European Tyre and Rim Technical Organisation
394:European Tyre and Rim Technical Organisation
659:
645:
637:
89:United States Department of Transportation
67:, is a set of standards for passenger car
237:
224:
216:
305:
410:
7:
1207:Uniform Tire Quality Grading (UTQG)
575:"Consumer Tire Information Program"
25:
27:Standards for passenger car tires
1230:
1229:
1219:
200:Relation to friction coefficient
182:Goodyear Tire and Rubber Company
1063:Tire-pressure monitoring system
1261:Standards of the United States
83:. The UTQG was created by the
1:
1053:Central Tire Inflation System
600:"Tire Tech Information: UTQG"
462:Cornell University Law School
61:Uniform Tire Quality Grading
36:UTQG ratings on sidewall of
1174:Tire Science and Technology
694:Low rolling resistance tire
1292:
437:Rubber & Plastics News
63:, commonly abbreviated as
1215:
562:HPwizard on Tire Friction
87:in 1978, a branch of the
52:(bottom) on sidewall of
1015:Slip (vehicle dynamics)
972:Lateral Force Variation
922:Pacejka's Magic Formula
902:Cold inflation pressure
71:that measures a tire's
48:UTQG ratings (top) and
1111:List of tire companies
982:Traction (engineering)
977:Radial Force Variation
250:
77:temperature resistance
57:
41:
962:Tire load sensitivity
251:
124:and above along with
47:
35:
1266:1978 in American law
942:Self aligning torque
625:Tire Safety brochure
215:
206:friction coefficient
56:ContiProContact tire
1068:Tire-pressure gauge
704:Michelin PAX System
421:. January 28, 2011.
308:
1271:1979 introductions
1106:Tire manufacturing
937:Rolling resistance
306:
283:possibly receive.
246:
58:
42:
1276:Automotive safety
1243:
1242:
932:Relaxation length
809:Formula One tyres
433:"UTOG CHRONOLOGY"
366:
365:
318:Concrete g force
244:
163:San Angelo, Texas
16:(Redirected from
1283:
1233:
1232:
1225:Outline of tires
1223:
1038:Tire maintenance
987:Treadwear rating
897:Circle of forces
819:Continental tire
759:Orange oil tires
749:Mud-terrain tire
729:All-terrain tire
661:
654:
647:
638:
612:
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515:Consumer Reports
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315:Asphalt g force
309:
307:Traction Grades
261:braking distance
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967:Tire uniformity
927:Pneumatic trail
917:Ground pressure
912:Cornering force
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852:Siping (rubber)
823:
794:Motorcycle tyre
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535:Weiss, Sandra.
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40:Proxes R39 tire
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5:
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1184:Identification
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1146:Ozone cracking
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1126:Tire recycling
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952:Steering ratio
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872:Schrader valve
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764:Whitewall tire
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619:External links
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602:. TireRack.com
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359:Less Than 0.38
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1156:Organizations
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1043:Tire rotation
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1021:
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1010:Groove wander
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907:Contact patch
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892:Camber thrust
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769:Aircraft tire
767:
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712:
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699:Run-flat tire
697:
695:
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690:
687:
685:
684:Tubeless tire
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669:
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541:www.nhtsa.gov
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490:www.nhtsa.gov
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122:medium trucks
119:
115:
110:
107:
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100:
98:
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90:
86:
82:
78:
74:
70:
66:
62:
55:
51:
46:
39:
34:
30:
19:
1169:Tire Society
1083:Tire changer
1078:Bead breaker
1048:Bicycle pump
957:Tire balance
867:Presta valve
862:Dunlop valve
804:Racing slick
799:Tractor tire
784:Tubular tire
779:Bicycle tire
709:Airless tire
631:SaferCar.gov
627:by the NHTSA
604:. Retrieved
594:
584:September 7,
582:. Retrieved
569:
556:
544:. Retrieved
540:
530:
518:. Retrieved
514:
505:
493:. Retrieved
489:
477:
465:. Retrieved
461:
452:
440:. Retrieved
436:
427:
413:
389:Wheel sizing
372:
301:
297:
293:
285:
281:
278:
274:
265:
258:
203:
179:
171:public roads
160:
151:
147:
139:
111:
108:
101:
64:
60:
59:
29:
1197:Plus sizing
1121:Waste tires
1073:Direct TPMS
1058:Tire mousse
1030:Maintenance
1005:Aquaplaning
774:Tundra tire
754:Paddle tire
739:Knobby tire
689:Radial tire
369:Temperature
271:Limitations
157:Methodology
114:motorcycles
54:Continental
1250:Categories
1202:Tire label
1098:Life cycle
1020:Tramlining
947:Slip angle
884:Attributes
857:Valve stem
829:Components
814:Spare tire
744:Large tire
405:References
399:Tyre Label
348:Above 0.38
337:Above 0.47
326:Above 0.54
175:West Texas
136:Components
38:Toyo Tires
1192:Tire code
1141:Flat tire
1131:Tire fire
1088:Tire iron
997:Behaviors
789:Lego tire
724:Snow tire
719:Rain tyre
606:April 23,
520:August 6,
467:August 6,
442:August 6,
384:Tire code
219:μ
144:Treadwear
93:tire code
73:treadwear
50:tire code
1235:Category
842:Beadlock
734:Bar grip
378:See also
290:Traction
186:Uniroyal
126:trailers
81:traction
1136:Blowout
1116:Retread
580:. NHTSA
546:May 9,
495:May 9,
312:Grade
167:convoy
1256:Tires
847:Tread
714:Tweel
676:Types
668:Tires
578:(PDF)
486:(PDF)
362:0.26
351:0.26
340:0.35
329:0.38
130:FMVSS
118:buses
69:tires
837:Bead
608:2013
586:2012
560:See
548:2019
522:2016
497:2019
469:2016
444:2016
239:0.15
227:2.25
102:The
79:and
65:UTQG
18:UTQG
173:in
1252::
539:.
513:.
488:.
460:.
435:.
323:AA
196:.
120:,
116:,
99:.
75:,
660:e
653:t
646:v
610:.
588:.
564:.
550:.
524:.
499:.
471:.
446:.
356:C
345:B
334:A
235:W
231:T
222:=
194:1
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
