Tyre aging occurs as a result of the natural degradation (oxidation) of the rubber compounds over time. This aging process is accelerated by exposure to heat and sunlight. Tyres age faster in warmer coastal climates than they do in cold climates.
Poor storage conditions and infrequent use accelerates the aging process.
In most applications tyres will complete service life before they are affected by aging.
Infrequently used tyres are prone to aging. Examples of these are tyres on a caravan, trailer and the spare tyre of a vehicle.
Visible signs of aging appear as small hairline type of cracking, normally on the sidewall of a tyre.
The SATMC recommend that tyres which are 7 years older than their production date be replaced.
Determining the chronological Age of tyres from their production date.
This can be determined from the characters following the symbol “DOT” on the sidewall of a tyre.
For tyres manufactured after 1999, the last four digits represent the week and year of production. The first two are the week of manufacture and range from 01 to 53. The last two represent the year of manufacture. For example; “ DOT xxxxxxx2712 “ was manufactured in the 27th week of 2012.
E-Mark tyres have a four digit code on the sidewall eg. 3712 meaning it was made in week 37 of 2012.