Tires, Aging
- Even tires that look in good shape, new or hardly use and have sufficient tread depth can age due to moisture and winter conditions.
- Tire test show that through continual development, new rubber mixtures, modern raw materials and optimizing the tire profile and profile geometry, better tires are being produced.
- The highly engineered vehicles plus constant growing customer expectations, demand economical tires that offer the highest degree of safety, driving dynamic and comfort, that only tires from the newest technology can provide.
- Tires age as a result of physical and chemical processes whereby the function can be impaired.
- 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 tire's production date.
Example of a DOT number through 12/31/1999
| DOT | ...... | 5 | 0 | 9 | < | |
| stands for 199_ | ||||||
| Production year last digit | ||||||
| Calendar week | ||||||
In this example, the production date is 12/13/1999.
Example of a DOT number from 01/01/2000
| DOT | ...... | 0 | 1 | 0 | 0 | |
| Production year last two digits | ||||||
| Calendar week | ||||||
In this example, the production date is 01/03/2000.
The original characteristics of summer and winter tires are reduced by the aging process. The gripping capabilities of winter tires are especially reduced.
Pay attention to the applicable country-specific requirements / laws for changing a tire.
When new tires are fitted, the spare tire may also be used if it is in flawless condition. 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 car's handling.
Tires are constantly being further 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.
FWD Vehicles:
For driving safety reasons, tires of the same make and with the same tread should be mounted on one axle.
AWD Vehicles:
AWD vehicles must always be equipped with four wheels with tires of the same size, construction type, 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.
- There is visible damage due to aging, for example tears or discolorations.