Information About Tires
Information about tires
Lettering on tire side wall
Example: Dunlop SP Sport 9000
1 - Size designation (215/55 ZR16)
2 - Manufacturer (trade name)
3 - Tread designation
4 - Identifier for tubeless tires
5 - Radial construction (radially-oriented fibers in carcass)
6 - Information on version with flange protection
7 - Manufacture date - see tire aging
8 - E number Approval number. Tire fulfills European Guidelines ECE-R30 and EEC92/93
9 - Country of manufacture - manufactured in Germany.
10 - Internal tread code of DUNLOP
11 - Department of Transportation - the tires fulfill the guidelines from the American transportation authorities
12 - Example: Dunlop SP Sport 9000
DOT - code identification number for manufacturers factory, tire size and tire version
13 - Maximum permitted load and maximum permitted tire pressure specifications for North America
14 - Number of ply layers in the center of the tread and in the sidewalls and information about the material
15 - Position of TWI tread wear indicator
16 - Relative service life expectancy - abrasion resistance - based on a US-specific standard test
17 - Evaluation of wet braking ability A, B or C according to US-specific test
18 - Evaluation of temperature stability A, B or C according to US-specific test
19 - Safety notes for use or mounting of tires
20 - Indication of "Ultralight construction"; tires are up to 30% lighter
21 - Specified direction of travel of tire
22 - In metro designation, only necessary for Brazilian market
Tires with emergency running characteristics, SST (Self-Supporting Tire) and PAX, have a special designation on the tire side wall, depending on manufacturer.
Tires with emergency running characteristics (PAX), lettering on side wall
1. Tire width
2. Aspect ratio in
3. Tire construction code R means radial
4. Rim diameter designation
5. Load index
6. Speed code
7. Winter tire/designation for all-season tire
Speed code/high speed
Load index (LI)
^ The load capacity index can be found on the sidewall of the tire. It provides information about the maximum load that the tire can bear.
^ The load capacity index is located in the size designation, e.g. 195/15 R 91 91T, of the tire. It is indicated on the tire as a code according to ETRTO. The following table shows the load capacity index used at VW/Audi with the corresponding load capacity of the tires.
Cracking
Cracking is the term for shallow cracks in the sidewall of the tire.
They run starting from the bulge in the direction of the tire shoulder.
See Illustration for the mentioned components.
The cause is the increase in material at the joints of the tire components.
Cracking has no effect on:
^ Safety,
^ Service life,
^ Driving behavior or other tire characteristics.
Cracks can be of varying visibility. Removing the tire from the rim or an examination is not necessary.
How did the cracks form?
Modern steel belted tires are constructed with single-ply sidewalls to save weight.
The sidewall components consist of long strips before they are joined together to form a tire. They must overlap at the joints. Small irregularities/ripples form in the area of the overlapping components. The overlaps are easier to see from the outside due to the single-ply construction.
The rubber valve
1. Valve body
2. Valve core
3. Valve cap
1. The valve body
^ The rubber valve for tubeless tires is designed to seal air-tight in the hole in the rim. The elastic material of the rubber body presses itself tightly into the hole in the rim.
^ When valves with threaded metal feet are used, a rubber seal is used to seal the rim. The area around the edge of the valve hole is a sealing area. Therefore, they must be free of rust, dirt and damage.
2. The valve insert
^ The valve core has the most important job in the valve: It creates a seal and enables the regulation of the air pressure. The small plate seal on the valve core can only do its job when it is free of impurities, dirt and moisture.
3. Valve cap
^ A valve cap must always be installed onto the valves. It prevents dirt from getting into the valve. Dirt which may be in the valve would reach the seal of the valve plate when the tire is inflated and cause a leak.
^ The valve must be replaced every time a new tire is installed.
^ If the vehicle is driven without caps on the valves, there is the danger that dirt may get into the valve. This leads to gradual loss of air and therefore lead to the destruction of the tire, Tire damage
Note:
^ CAUTION! An air tight seal is ensured only if the valve cap is secured tightly.
Tire storage
The storage room
Tire storage must be
^ Dark,
^ Dry,
^ Cool,
^ Ventilated.
Stored tires must not come in contact with fuel, oil, grease or chemicals under any circumstances. Otherwise, the material in the tire will be damaged by chemical reactions which are not always visible.
This may lead to life-threatening situations when the car is driven. However, tire damage occurs only when the reaction time of the chemicals is long. If a few drops of fuel land on a tire during a fill-up, this is harmless.
Tire storage
Complete wheels
Tires mounted on wheels can be stored flat, stacked upon another. The air pressure should be raised to a maximum of 3 bar.
Tires without wheels
Tires without wheels are best stored standing vertically. If tires lie stacked upon another for longer periods of time, they will be strongly pressed together. This makes mounting more difficult because the tires do not lie on the rim shoulder. If the tires are stored standing vertically, it is recommended to turn them every 14 days to avoid severe flattening.
Tire aging
Tires age as a result of physical and chemical processes whereby the function can be impaired. Tires which are stored for longer periods of time become harder and brittle faster than tires which are constantly in use on a vehicle. Older tires may develop hairline cracks from aging. When tires are in constant use, the kneading activates softeners in the rubber, preventing hardening and the development of cracks.
Therefore, one should note not just the tread depth but also the age of spare tires, stored tires and tires which are not permanently in use. Tire age can be determined from the DOT code which contains, among other things, the tires production date.
Example of a DOT number:
In this example, the production date is the 50th week in 2002. Through 12/31/1999, the DOT number was a three-digit number.
Recommendation:
^ It is recommended using tires more than 6 years old only in emergencies and only with a cautious driving style.
^ When new tires are installed, the spare tire may also be used if it is in flawless condition and is not more than 6 years old. The age of the tire has a great influence on the high-speed capability of the tire. The combination of a spare tire which is several years old with new tires is possible, but it can influence the cars handling.
^ Tires are constantly being developed, this can lead, for example, to slight changes in the rubber compound, even if the tires are of the same make, size and tread.
^ For safety reasons, tires of the same make and with the same tread should be mounted on one axle. All Audi and VW vehicles are factory-installed with four identical tires and wheels.
^ Vehicles with four-wheel drive always must be equipped with four wheels that have tires of the same size, construction, tread pattern and make.
Tires, replacing
Tires must be changed when:
^ The legal minimum tread depth of 1.6 mm is reached,
^ There is visible damage from mechanical damage,
^ Tires are more than 6 years old.
Care and treatment of light alloy wheels
To maintain the decorative appearance of light alloy wheels for a long time, regular care is necessary.
In particular, road salt and dust from brake abrasion must be thoroughly washed off every 2 weeks. Otherwise, the paint of the light alloy wheel will be attacked.
The following are appropriate cleaning agents:
^ Water or water and soft soap
^ Water and vinegar essence
^ Light alloy wheel cleaning agents without acids or harsh solvents
Do not exceed the soaking time of the cleaning agent.
The shorter the specified soaking time is, the stronger and more aggressive the cleaning solution is.
If the paint is damaged, for example by impact from a stone, the paint damage must be repaired immediately.
Remove adhesive residue from light alloy rim adhesive balancing weights:
^ Harsh solvents and acids attack the paint on light alloy wheels and the surface of the wheel becomes matte and milky. These agents therefore must not be used.
^ To remove adhesive residue on light alloy wheels, use light alloy cleansers or benzene based cleanser. Do not exceed the soaking time of the cleaning agent.
^ After cleaning or removing adhesive residue on the tires, they must be rinsed again with water.
Wheels, rotating:
^ Vehicles with front-wheel drive experience more tread wear on the front wheels due to the increased stress on them.
^ In order for all 4 wheels on the vehicle to have the same service life, it is recommended to rotate the front and rear wheels.
^ Ensure that uni-directional tires are not reversed.
^ The longer the tire runs at one position, the more it wears at certain points, therefore, it is recommended to rotate the wheels at short intervals, e.g. every 5,000 km.
^ Diagonal rotation is possible only with non-directional tires. This wheel rotation is especially advantageous for heel-and-toe wear. Heel-and-toe wear.
^ If heel-and-toe wear has already progressed very far and the tread is more than 50% worn, only slight improvement can be achieved and rotation is no longer recommended. The elasticity of the tread blocks declines and the heel-and-toe wear does not progress.