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# Symbols of car tires

The car tire is one of the most important elements of the wheel, which is an elastic rubber-metal-fabric shell, mounted on the rim of the disk. The tire provides contact of the vehicle with the roadway, it is designed to absorb minor fluctuations caused by imperfections in the road surface, compensation of the error of the trajectory of the wheels, the realization and perception of forces.

## Size

The size is written on the sidewall of the tire.

For example: 195/65 R 15 91T where:

• 195 is the width of the tire in mm.
• 65 is the percentage of the height of the profile of the tire to its width (in our case, 65%). This parameter determines the height of the bus for a given bus width. Note that as the tire width increases, with the same profile value, the tire height also increases! If this number is not on the sidewall of the tire (for example 195 / R 15), then this value is equal to 80% and such a tire is called "full profile".
• R - means the design of the tire (radial). Many motorists mistakenly think that R is the radius of the tire. Car tires with a diagonal design is almost not produced.
• 15 is the diameter of the disc in inches; The internal diameter of the tire (namely diameter, not radius).
• 91 - tire load index. This is a conditional indicator that determines the maximum load on the bus.

Using the table, you can find out the maximum load in kilograms, at which the tire manufacturer ensures that the tire does not collapse and will show the specifications specified by the manufacturer.

 Index of the load. 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 Mach. Load (in kg) 335 345 355 365 375 387 400 412 426 437 460 462 475 787 500 515

 Index of the load. 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 Mach. Load (in kg) 515 530 545 560 580 600 615 630 650 670 690 710 730 750 775 800

 Index of the load. 101 102 103 104 105 106 107 108 109 110 111 113 114 115 116 Mach. Load (in kg) 825 850 875 900 925 950 975 1000 1030 1060 1090 1150 1180 1215 1250

 Index of the load. 117 118 119 120 121 122 123 124 125 126 127 128 129 130 Mach. Load (in kg) 1285 1320 1360 1400 1450 1500 1550 1600 1650 1700 1750 1800 1850 1900

Some tires say MAX LOAD (maximum load) and then stand in kilograms and pounds.

For minibuses and light trucks special, multi-layer reinforced tires with high load indexes are produced. And, depending on the load index, they are indicated by the inscription REINFORCED (6 layers, reinforced tire) or the letter " C " after the tire diameter, for example: 195/70 R 15 C, (8 layers, truck tire).

T is the velocity index. This conditional parameter determines the maximum permissible speed of the car, allowed when using these tires.

 Index of fast. J K L M N P Q R S T U H V VR W Y ZR Mach. Speed (km / h) 100 110 120 130 140 150 160 170 180 190 200 210 240 > 210 270 300 > 240

### American type designation

There are two types of marking of American tires.

The first is very similar to the European one, only in front of the standard size is the letter " P " (Passanger - for a car) or " LT " (Light Truck). For example: P 195/60 R 14 or LT 235/75 R 15.

And another marking, which is fundamentally different from the European one.

For example: 31x10.5 R15 , where:

• 31 - outer diameter of the tire in inches.
• 10.5 - The width of the tire in inches.
• 15 - internal diameter of the tire in inches.

### Additional designations used by tire manufacturers

* - The tire is recommended for BMW cars (does not exclude use on other cars).

BLK - black marks on the sidewall of the tire.
BSL - black notches on the sidewall of the tire.
BSW - black sidewall of the tire (in the tire brand designation).
BW - black sidewall of the tire.
C * S - the tire withstands up to 50 punctures.
DSST - Dunlop Self-Supporting Technology - see ROF.
EMT - technology of tireless tires from Goodyear - see ROF.
G1 - it is mandatory to use the same tires on the same axis.
Left - The tire is designed for installation on the left side of the car.
LT is a tire for a light truck.
M + S - (also written as M & S or MS) - indicates a multigrade application. Also this inscription can be seen not only on all-season, but also on winter tires. Summer tires usually do not have such designations. To obtain such a designation, the tire should have a special percentage of the tread to the voids, however this does not mean that the tires were tested in harsh conditions.
MFS - maximum rim protection system protects expensive wheels from damage from curbs and sidewalks - the rubber profile along the circumference of the tire, located on the bottom of the wall above the flange of the rim, forms a buffer zone.
MO - the tire is recommended for cars of group Mersedes (does not exclude use on other cars).
N0 / N1 / N2 / N3 / N4 / N5 - the tire is recommended for Porsche vehicles (not recommended for use on other cars).
OBL - highlighted black marks on the sidewall of the tire.
ORBL - highlighted raised black marks on the sidewall of the tire.
ORWL - highlighted raised white marks on the sidewall of the tire.
OWL - contour white marks on the sidewall of the tire.
RBL - relief black marks on the sidewall of the tire.
RF / XL - reinforced tires - for vehicles with increased load capacity.
Right - the tire is designed for installation on the right side of the car.
RO1 - the tire is recommended for cars Audi Quattro.
ROF - (RunOnFlat, RunFlat) RunOnFlat tires, formerly known as EMT, RunFlat is a technology that allows your car to continue driving after a puncture or descent of a tire. Even if the tire pressure is lost completely, this technology allows the car to pass a minimum of 80 km, at a speed of up to 80 km / h. Reinforced tires, as a rule, have in the lateral parts of several layers of rubber with heat resistant cord, which, with complete loss of pressure, do not allow the sidewalls of the tire to fold or crumple.
ROWL - relief contour white marks on the sidewall of the tire.
RRBL - recessed relief black marks on the sidewall of the tire.
RWL - relief white marks on the sidewall of the tire.
SBL - jagged black marks on the sidewall of the tire.
VO - the tire is recommended for cars of group Volkswagen Touareg (does not exclude use on other cars).
VSB - vertical serrated strip on the sidewall of the tire.
WS - white stripe on the sidewall of the tire.
WSW - white stripe on the sidewall of the tire.
WW - white wall.

## Examples

### Metric system

Example: LT205 / 55R16 91V

• LT (optional, mandatory DOT designation) - bus function (P - passenger car, LT - light truck, ST - for trailers / trailers, can not be used for cars / pickups / trucks T - temporary (used only for spare tires))
• 205 - profile width, mm
• 55 is the ratio of the profile height to the width,%. If not specified, it is considered equal to 82%.
• R - the tire has a skeleton of a radial type (if there are no letters - a bus of a diagonal type). A common mistake is that R is taken as the letter of the radius . Possible variants: B-bias belt (the tire carcass is the same as for the diagonal tire, but there is a belt as for a radial tire), D or not specified - the diagonal type of the frame.
• 16 - landing diameter of the tire (corresponds to the diameter of the rim of the disc), in.
• V - speed index (determined by the table)

Possible variations:

• The speed index can be located in different places of marking: 225/50 S R16, 225/50 S R16 89 S , 225 / 50R16 89 S
• The presence of the letter C after the diameter, for example, 195 / 70R15 C 104 / 102R, means "commercial". This tire is designed for pickups or trucks with increased load capacity.
• After the size, the letters XL, RF, SL, LL (for example, P235 / 75R-15 XL , P285 / 35R-19 LL ) can be present. They mean respectively increased (extra load, reinforced), standard (standard load), and reduced (light load) load capacity. In the American P-marking XL corresponds to a maximum permissible pressure of 41 psi (280 kPa), SL and LL is 35 psi (240 kPa), in the European XL / RF marking corresponds to 42 psi (290 kPa), SL - 36 psi (250 kPa) , LL is absent. The absence of this designation corresponds to the variant SL.
• The letters FR (for example, 215/45 R17 87V FR ) after the size mean a tire with rim protection. The protective edge on the sidewall of the low profile tire protects the disc and the sidewall of the tire itself from damage when the road surface irregularities travel at high speed.
• In rare cases (for example, for Michelin tires with the PAX system), the landing diameter can be specified in millimeters, for example, 190 / 65R 390 , such tires are called millimeters. If after the diameter there is a letter A - this means an asymmetric landing rim, i. E. different internal and external diameters of the landing rim. For example, in the case of the 235 / 710R460 A 104T, the inner landing diameter will be 470 mm and the outer diameter 450 mm. Millimeter tires along with inch disks and vice versa - millimetric disks with inch tires - can not be combined and used.

### Inch system

Example: 35x12.50 R 15 LT 113R

• 35 - outer diameter of the tire, in inches
• 12.50 - the width of the tire, in inches (note that this is the width of the tire, not the tread part. For example, for a tire with a specified width of 10.5 inches, the width of the tread portion will not be 26.5 but 23 cm, and the protective portion of 26.5 cm will be tires with a specified width of 12.5.). If the outer diameter is not specified, the profile is calculated as follows: if the width of the tire ends at zero (for example, 7.00 or 10.50), then the profile height is considered equal to 92%, if the width of the tire does not end to zero (for example, 7.05 or 10.55) is considered equal to 82%
• R - the tire has a skeleton of a radial type
• 15 - landing diameter of the tire, in inches, the same as in the metric system
• LT - bus function (LT - light trucks, for light trucks)