Tires, Aging

WARNING: This page is about a different variant/trim than selected.

Even tires that look in good shape, new or hardly use and have sufficient tread depth and that are older than six years, can age caused by 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. 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 tire's production date.

Example of a DOT number through 12/31/1999

In this example, the production date is the 50th week of 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 the 01st week of 2000.

Recommendation

Using summer and winter tires that are more than 6 years old is not recommended. The aging process reduces the original characteristics. The gripping capabilities of winter tires are especially reduced.
When new tires are fitted, 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 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.
All vehicles are factory-fitted with four identical tires and wheels.

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: