During the change of seasons for many owners, the question of replacement tires….what do the numbers and letters on the sidewall of a vehicle wheel.
During the change of seasons for many owners, the question of replacement tires. In addition to the logical selection of summer, winter or all-season rubber, you need to choose the right size, load level and speed according to vehicle characteristics. You can find this information in the user manual of the vehicle. And all the necessary information about the tire is contained on the sidewall. Knowing what and where it is written, you can make a much better vision of the future wheel.
The most important information about the tire is its size.
Most often it is specified in the metric system, at least – inches and consists of 6 groups of characters.
The first group of three digits indicates the width in millimeters.
The second is ambiguous – the ratio of the height profile and width in percent.
The letter R tells about the radial structure of the tyre, then the rim diameter in inches.
Individual digits represent the load index, which indicates the maximum permissible load on the tire. It approximately can be calculated by dividing the gross weight of the vehicle by 4 (number of wheels).
Completes the inscription of a letter indicating the speed rating. It corresponds to the speed at which can accelerate the car.
Except for the name of the manufacturer and the tire model, it still contains a lot of additional information
Very important are data about conditions of use tyres according to season and cover.
Latin letters AS ( All Season, any season ), or AW ( Any Weather ) show that a tire can be used at any temperature. Tire marks R + W (road + Winter ) can be used in winter and on asphalt. Character * ( snowflake ) – marking winter tires. Depending on the available coatings, which must be the wheel can be letters: M & S ( Mud + Snow ) – mud plus snow, A / T ( All Terrain ) – all-terrain, M / T ( Mud Terrain ) off-road.
may have a mark that you can use them in the rain, and marked one of these words: Aquatred, Aquacontact, rain, water, Aqua and icon “umbrella “.
It should be borne in mind that the image of the sheet of wood on the tire refers to its annual use. This icon makers mark rubber, which has a low rolling resistance that reduces fuel consumption, and / or using eco – friendly materials.
Winter studded tires
there is a separate marker denoting various types of spikes :
N. e. – aluminum studs ;
SD – spikes with carbide core ;
DD – spikes with a rectangular core and a diamond pattern ;
OD – spikes with oval core ;
MD – plastic studs with carbide core.
For tires with directional and / or asymmetrical tread pattern it is important to specify for their installation – which side and in what direction to raise the wheel.
They can be marked the following words and symbols :
Outsade or Side Facing Out – the external fitting;
Inside or inward Side, the inner fitting;
Rotation and the arrows indicate the direction of movement;
Left – tire installed on the left side of the vehicle;
Right – the tire is installed on the right side of the car.
Modern tires can be additional technologies that can improve safety if the wheel is loose or was broken
System protection upon loss of pressure from different manufacturers have different names but work practically the same way to the bus embedded additional layer of elastic material, which some time keeps the necessary movement for height. They referred to markaveli : SSR ( self-supporting after a puncture ), DSST ( Dunlop Self – Supporting technology), EMT (Extended Mobility Technology ), replaced with a RunOnFlat, RFT ( Run-Flat tires) or zero pressure. Cheap security system – installation in tire tight (sometimes metal ) rim next to the wheel rim, becomes a support for run-flat tire. Such systems may be indicated by the abbreviation CSR ( ContiSupportRing ), FR ( Flange Rotector ), MFS ( Maximum Flange Shield ). Often these technologies are used only in the presence of the monitoring system tire pressure ( TPMS or DDS ), which will signal the driver about the problem.
Before the size can be specified bus function:
G ( Passenger car) passenger car ;
LT ( Light Truck ) – light truck, pick-up or SUV ;
ST ( Special trailer ) – trailer ;
LRO (low Platform Trailer ) – trailer with low platform ;
T ( time) – temporary, spare tire.
In addition, there may be the following notation:
XL ( Extra Load ) – enhanced bus ;
Of the Russian Federation ( enlarged ) – reinforced tyre with higher carrying capacity ( 6 layers) ;
End size – truck tire ( 8 layers) ;
Tubeless or tube Type – tubeless tyre. In the absence of this inscription, the bus can only be used with the camera.
Maximum pressure – maximum allowable tyre pressure, in kPa;
Maximum load – the maximum permissible tyre load, in kg;
Steel – means that the design of the bus is metal cord ;
E / E17 ( circle ) – the tire conforms to European standards ECE ( economic Commission for Europe ) ;
DOT / dot is an American standard for quality ( Department of transport – Ministry of transportation
Temperature A, b or C – resistance tires at high speeds on the test bench (the best indicator ) ;
Anti slip A, b or C – the ability of the tyre to brake on a wet road surface ;
On a run – relative expected mileage compared to the special standard test of the United States ;
Protector layers – composition layer of the tread ;
Side wall – composition layer sidewall ;
DA (stamp ) – insignificant industrial defects, not preventing normal operation ;
Twid – presence indicator wear indicator on the projector. The indicator is a protrusion on the bottom of the tread grooves. When the tread wears to the level of this ledge, the tire time to change ;
N0, N1, N2 and N3 is a tyre designed for the Porsche ;
J – bus developed for the Jaguar.