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National technical standards regulations The European Tyre and Rim Technical Organisation (ETRTO) and the Tire and Rim Association (TRA) are two organizations that influence national tire standards. The objective of the ETRTO include aligning national tire and rim standards in Europe. The Tire and Rim Association, formerly known as the The Tire and Rim Association of America, Inc., is an American trade organization which standarizes technical standards. In the United States, the Office of Vehicle Safety Compliance, a component of the Department of Transportation, is one of the agencies tasked to enforce the Federal Motor Vehicle Safety Standard (FMVSS). Canada has published tire regulations, such as the Motor Vehicle Tire Safety Regulations SOR 95-148. Explanation of tire codes Tire identification diagram Tire identification diagram, light truck specific features The ISO Metric tire code consists of a string of letters and numbers, as follows: An optional letter (or letters) indicating the intended use or vehicle class for the tire:- P: Passenger Car LT: Light Truck ST: Special Trailer T: Temporary (restricted usage for "Space-Saver" spare wheels) Use of the letter P indicates that the tire is engineered to TRA standards and absence of a letter indicates that the tire is engineered to ETRTO standards. In practice, the standards of the two organizations have evolved together and are virtually interchangable. 3 digit number: The "nominal section width" of the tire in millimeters; the widest point from both outer edges. /: Slash character for character separation. 2 or 3 digit number: The "aspect ratio" of the sidewall height to the total width of the tire, as a percentage. If the information is omitted, it is assumed to be 82%. If the number is larger than 200, then this is the diameter of the entire tire in millimeters. An optional letter indicating construction of the fabric carcass of the tire: B: bias belt (where the sidewalls are the same material as the tread, leading to a rigid ride) D: diagonal R: radial if omitted, then it is a cross ply tire 2 digit number: Diameter in inches of the wheel that the tire is designed to fit. There is the rare exception metric diameter tires, such as the use of the 390 size, which in this case would indicate a wheel of 390 mm in diameter. Few tires are made to this size presently. 2 or 3 digit number: Load index; see table below 1 or 2 digit/letter combo: Speed rating; see table below Additional marks: See subheading below. Light trucks Some light truck tires follow the Light Truck Numeric or Light Truck High Flotation systems, indicated by the letters LT at the end instead of the beginning of the sequence, as follows: The tire diameter is given for High Flotation tires and omitted from Numeric tires. 2 digit number: The diameter of the tire in inches. x: Separator character. 3 or 4 digit number: The section width (cross section) of the tire in inches. If the tire diameter is not given, section widths ending in zero (e.g., 7.00 or 10.50) indicate the aspect ratio is 92%, while section widths not ending in zero (e.g., 7.05 or 10.55) indicate the aspect ratio is 82%. Construction of the fabric of the tire: B: bias belt D: diagonal R: radial 2 digit number: Diameter in inches of the wheel rim that this tire is designed to fit. LT: Designates that this is a Light Truck tire. Load index and speed rating are not required for this type of tire but may be provided by the manufacturer. 2 or 3 digit number: Load index; see table below. 1 or 2 digit/letter combination: Speed rating; see table below. Additional marks: See subheading below. Load range Load range on light truck tires indicates ply rating and load pressure (PSI). Tire pressure is also measured in kilopascals or bars. 1 psi is equal to 6.895 kPa. 100 kilopascals is equivalent to one bar. Therefore, 300 kPa is equivalent to 44 psi. Load Range Load Range Ply Rating Load Pressure (PSI) B 4 35 C 6 50 D 8 65 E 10 80 F 12 95 Load index The load index on a passenger car tire is a numerical code stipulating the maximum load (mass, or weight) each tire can carry. For Load Range "B" tires, ETRTO standards specify the load index rating at an inflation pressure of 36 psi while TRA standards measure the load capacity at an inflation pressure of 35 psi. The two standards vary slightly with the capacity required for different inflation pressures. Load Index (E.T.R.T.O. 1991 - Section 13)[citation needed] Code Pounds Kilograms Code Pounds Kilograms Code Pounds Kilograms Code Pounds Kilograms 60 551 250 80 992 450 100 1,764 800 120 3,087 1,400 61 567 257 81 1,019 462 101 1,819 825 121 3,197 1,450 62 584 265 82 1,047 475 102 1,874 850 122 3,306 1,500 63 600 272 83 1,074 487 103 1,929 875 123 3,418 1,550 64 617 280 84 1,102 500 104 1,984 900 124 3,528 1,600 65 640 290 85 1,135 515 105 2,039 925 125 3,638 1,650 66 661 300 86 1,168 530 106 2,094 950 67 677 307 87 1,201 545 107 2,149 975 68 695 315 88 1,235 560 108 2,205 1,000 69 717 325 89 1,279 580 109 2,271 1,030 70 738 335 90 1,323 600 110 2,337 1,060 71 761 345 91 1,356 615 111 2,403 1,090 72 783 355 92 1,389 630 112 2,470 1,120 73 805 365 93 1,433 650 113 2,536 1,150 74 827 375 94 1,477 670 114 2,601 1,180 75 853 387 95 1,521 690 115 2,679 1,215 76 882 400 96 1,565 710 116 2,756 1,250 77 908 412 97 1,609 730 117 2,833 1,285 78 937 425 98 1,653 750 118 2,910 1,320 79 963 437 99 1,709 775 119 2,999 1,360 Speed rating The code is made up of one or two letters, or one letter and one number. It indicates the maximum permitted speed that the tire can sustain for a ten minute endurance without being in danger[citation needed]. Speed rating[citation needed] Code mph km/h Code mph km/h A1 3 5 L 75 120 A2 6 10 M 81 130 A3 9 15 N 87 140 A4 12 20 P 94 150 A5 16 25 Q 100 160 A6 19 30 R 106 170 A7 22 35 S 112 180 A8 25 40 T 118 190 B 31 50 U 124 200 C 37 60 H 130 210 D 40 65 V 149 240 E 43 70 Z over 149 over 240 F 50 80 W 168 270 G 56 90 (W) over 168 over 270 J 62 100 Y 186 300 K 68 110 (Y) over 186 over 300 Prior to 1991, tire speed ratings were shown inside the tire size, before the "R" character. The available codes were SR (112 mph, 180 km/h), HR (130 mph, 210 km/h), VR (in excess of 130 mph, 210 km/h) and ZR (in excess of 149 mph, 240 km/h). The ZR code is still in common use, often combined with a W or Y speed code. Tires with a speed rating higher than 186 mph (300 km/h) are indicated by a Y in parenthesis[citation needed]. The load rating is often included within the parenthesis, e.g. (86Y). In many countries, the law requires that tires must be specified, and fitted, to exceed the maximum speed of the vehicle they are mounted on, with regards to their speed rating code (except for "Temporary Use" spare tires). In the European community, tires that are not fit for a car's or motorcycle's particular maximum speed are illegal to mount. The sole exception are M+S tires, where a warning sticker stating the allowed maximum speed must be placed within clear sight of the driver inside the vehicle. Some manufacturers will install a speed governor if a vehicle is ordered with tires rated below the vehicle's maximum speed. If a tire is replaced with a lower speed rating than originally specified by the vehicle manufacturer, then this may render the vehicle insurance invalid. P-metrics Tires described "P-rated" or "P-metric" measure their tread width in millimeters. Unlike the older U.S. letter codes, the relationship between rim and tire width differs. Recommended tread width to rim width: P185:5in P195:5.5in P205:5.5in P215:6in P225:6in P235:6.5in P245:7in P255:7in P265:7in P275:8in P285:8in P295:8in P305:8in Additional marks There are numerous other markings on a typical tire, these may include: M+S, or M&S: Mud and Snow; all-weather tires, with above-average traction in muddy or very light snowy conditions, and for low ambient temperatures. Not a winter tire unless it has the snowflake and mountain symbol. Spike tires have an additional letter, "E" (M+SE). BSW: Black SideWall WSW: White SideWall OWL: Outline White Lettering E4: Tire approved according ECE-regulations, the number indicating the country of approval. 030908: Approval number of the tire DOT code: All tires for use in the USA have the DOT code, as required by the Department of Transportation (DOT). It specifies the company, factory, mold, batch, and date of production (2 digits for week of the year plus 2 digits for year; or 2 digits for week of the year plus 1 digit for year for tires made prior to 2000). Although not law, some tire manufacturers do not suggest using a "new" tire that has been sitting on the shelf for more than 6 years (Ford Motor Company) or 10 years (Cooper Tire citing a tire association recommendation).[citation needed] TL: Tubeless TT: Tube-type, tire must be used with an inner-tube Made in ...: Country of production C: Commercial; tires for light trucks (Example: 185 R14 C) B: Bias belted; tires for motorcycles (Example: 150/70 B 17 69 H)iagonal construction with belt added under the tread SFI, or Inner: Side Facing Inwards; inside of asymmetric tires SFO, or Outer: Side Facing Outwards; outside of asymmetric tires TWI: Tread Wear Indicator; a device, such as a triangle or a small Michelin Man icon, located where the tread meets the sidewall. It indicates the location of the raised wear bars in between the tire tread channels. SL: Standard Load; tire for normal usage and loads XL: eXtra Load; tire for vehicles of heavier standard weights RF: Reinforced tires Arrows: Some tread designs are "directional", and designed to perform better when driven in a specific direction (clockwise or counter-clockwise). Such tires will have an arrow showing which way the tire should rotate when the vehicle is moving forwards. It is important not to put a "clockwise" tire on the left hand side of the car or a "counter-clockwise" tire on the right side. M0: Original tires for Mercedes-Benz N*: Original tires for Porsche "Star": Original tires for BMW To facilitate proper balancing, most high performance tire manufacturers place laso red (uniformity) and yellow (weight) dots - marks on the sidewalls of its tires to enable the best possible match-mounting of the tire/wheel assembly. Tire geometry When referring to the purely geometrical data, a shortened form of the full notation is used. To take a common example, 195/55R16 would mean that the nominal width of the tire is approximately 195 mm at the widest point, the height of the side-wall of the tire is 55% of the width (107 mm in this example) and that the tire fits 16 inch diameter wheels. The code gives a direct calculation of diameter. Less commonly used in the USA and Europe (but often in Japan for example) is a notation that indicates the full tire diameter instead of the side-wall height. To take the same example, a 16 inch wheel would have a diameter of 406 mm. Adding twice the tire height (2107 mm) makes a total 620 mm tire diameter. Hence, a 195/55R16 tire might alternatively be labelled 195/620R16. Whilst this is theoretically ambiguous, in practice these two notations may easily be distinguished because the height of the side-wall of an automotive tire is typically much less than the width. Hence when the height is expressed as a percentage of the width, it is almost always less than 100% (and certainly less than 200%). Conversely, vehicle tire diameters are always larger than 200 mm. Therefore, if the second number is more than 200, then it is almost certain the Japanese notation is being usedf it is less than 200 then the U.S./European notation is being used. One might think that only the face diameter of the wheels are at issue; there seems to be no specification of the tire's fitment width, or what the nominal width at the wheel must be for a tire to fit onto that wheel. However, since wheels are manufactured in different widths, this information would seem to be an important omission from the standards. Examples The tires on a BMW Mini Cooper might be labeled: P195/55R16 85H P these tires are for a passenger vehicle. However 'P' denotes P metric size load & speed rating changes for P tire & non- P tires. 195 the nominal width of the tire is approximately 195 mm at the widest point 55 indicates that the height of the sidewall of the tire is 55% of the width (107 mm) R this is a radial tire 16 this tire fits 16 inch diameter wheels 85 the load index, a maximum of 515 kg per tire in this case H the speed index, this means the maximum permitted speed, here 210 km/h (130 mph). The tires on a Hummer H1 might be labeled: 37X12.5R17LT 37 - the tire is 37 inches in diameter 12.5 - the tire has a cross section of 12.5 inches R - this is a radial tire 17 - this tire fits 17 inch diameter wheels LT - this is a light truck tire. Tractor tires The numeric codes on tractor tires since 1955 have required either two or three numbers: W-D or H/W-D where 'W' is the width of the tire in inches, D is the diameter of the rim in inches and H (if provided) is the percentage height of the tire. Hence, 5.00-15 is a tire that will fit a 15 inch diameter rim and is 5 inches wide but of indeterminate height. 25/5-16 is a tire that has a 5 inch width, fits a 16 inch diameter rim and whose height is 25% of the width. References ^ [ http://www.etrto.org/page.asp?id=1685&langue=EN About us], European Tyre and Rim Technical Organisation. Retrieved 2010-01-05. ^ Scope of the Association and Some of its History, The Tire and Rim Association. Retrieved 2010-01-04. ^ Laboratory Test Procedure for FMVSS 120, National Highway Traffic and Safety Administration, United States Department of Transportation, April 10, 2000. Retrieved 2010-01-05. ^ Motor Vehicle Tire Safety Regulations SOR 95-148, Canadian Legal Information Institute. Retrieved 2010-01-05. ^ Care and Maintenance - Technical, Dunlop Tires. Retrieved 2010-01-05. ^ A brief history of radial tires and the offbeat TRX system, Michelin TRX, Dr. Theo Netherlands. Retrieved 2010-01-05. ^ Carga y presin de aire en Estados Unidos (Load and Pressure of Tires in the United States), Tire Rack. Retrieved 2010-01/05 ^ "Load Range/Ply Rating Identification". http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=55. Retrieved 2008-08-16. ^ Guidelines for the Application on Load and Inflation Tables, Toyo Tires. Retrieved 2010-01-05. ^ Hot Rod, 3/86, p.28. ^ "Tire care -- Match mounting", Yokohama Tire Corporation. ^ "FAQ's". http://www.millertire.com/FAQs.asp. Retrieved 2008-01-16. http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11 http://abcnews.go.com/Blotter/story?id=4813029&page=1 http://www.nhtsa.dot.gov/cars/rules/TireSafety/ridesonit/brochure.html See also Speedometer errors induced by variations in tire size. Tire manufacturing Uniform Tire Quality Grading (UTQG) Wheel sizing Plus sizing Motorcycle tires External links Visual Tire Size Calculator Tire / Wheel Size Calculator "Better Living by Reading Sidewalls" from Golden Gate Lotus Club Metric & Inches Tire Calculator Categories: Tires EncodingsHidden categories: All articles with unsourced statements Articles with unsourced statements from April 2008 Articles with unsourced statements from January 2010 The e-commerce company in China offers quality products such as China dual sim gsm phone , China dual sim watch phone, and more. For more , please visit branded dual sim phones today!
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