Tyre aging occurs very slowly to new tyres through chemical and physical processes only if the tyre is stored properly. When stored under the recommended conditions (cool, dry, away from direct light, chemicals and ozone sources), a tyre will maintain its original performance characteristics over a long period.
A properly stored, unused tyre up to 5 years old can be sold as a new tyre and placed into normal service if no local legal regulations are opposed to it. Note: The warranty period begins with the purchase date of the tyre.
Continental recommends that all tyres that are over 10 years old (as shown on the tyre’s date stamp) should be replaced with new tyres.
The chronological age of any tyre can be found on one of the tyre sidewalls by examining the four-digit manufacturing date stamp.
Usually but not exclusively, the date stamp follows the “DOT” marking and manufacturer related alpha numeric digits.
The last four numbers of the entire string identify the date of manufacture. The first two of these four numbers identify the week of manufacture (which range from "01" to "53"), the last two numbers identify the year of manufacture (e.g., a tyre with the information "DOT XXXXXXX4521” was manufactured in the 45th week of 2021).
The tyre industry has long recognised the importance of the consumers’ role in the regular care and maintenance of their tyres. The point at which a tyre is replaced is a decision for which the owner of the tyre is responsible. The tyre owner should consider factors such as service conditions, maintenance history, storage conditions, visual inspections, and dynamic performance. The consumer should consult a tyre service professional with any questions about tyre service life.
The following information and recommendations are made to help you decide when a tyre needs to be changed.
Tyres are designed and built to provide many thousands of miles of excellent service. For maximum benefit, tyres must be maintained properly to avoid tyre damage and abuse that may result in tyre disablement. The service life of a tyre is a cumulative function of the storage, rotation and service conditions, which a tyre is subjected to throughout its life (load, speed, inflation pressure, road hazard damage, etc.). Since service conditions vary widely, accurately predicting the service life of any specific tyre in chronological time is not possible.
The consumer plays an important role in tyre maintenance.
Tyres should be removed from service for numerous reasons, including tread worn down to minimum depth, damage or abuse (punctures, cuts, impacts, cracks, bulges, underinflation, overloading, etc.). For these reasons tyres must be inspected routinely, at least once a month. Regular inspection becomes particularly important the longer a tyre is kept in service. If tyre damage is suspected or found, Continental recommends that the consumer have the tyre inspected by a tyre service professional. Consumers should use this consultation to determine if the tyres can continue in service. This routine inspection should occur whether the vehicle is equipped with a tyre pressure monitoring system (TPMS) or not.
Consumers are strongly encouraged to be aware of their tyres’ visual condition. Also, they should be alert for any change in dynamic performance such as increased air loss, noise or vibration. Such changes could be an indicator that one or more of the tyres should be immediately removed from service to prevent a tyre disablement. Also, the consumer should be the first to recognise a severe in-service impact to a tyre and to ensure that the tyre is inspected immediately thereafter.