How Old Are My Tyres?
For the end user, knowing the age of a tyre is generally not high on the list of things-to-know. However tyre age can be important from a number of perspectives.
Legislation requires that a tyre be marked on at least one sidewall with the date of manufacture of the product. This is generally placed low on the tyre sidewall, appearing just above the flange of the wheel.
For passenger car and light truck tyres, the tyre will generally be fitted with this date facing outside. The legislation requires that this date be shown as the week and year manufacture. Historically this was denoted by three numeric digits, the first two representing the relevant week, the last one the year. Thus “458” denoted the 45th week of 1998. Or 1988…..
To avoid the obvious confusion which could occur with older tyres with respect to the year coding, at the turn of the century it was adopted internationally that the tyre date of manufacture code would be four digits.
Now, for example a tyre will show –
“3207” The 32nd week of 2007
Various tyre manufacturers have different ways of stamping pertinent information on the tyre sidewall. The international factory code will always appear first (two letters) then a series of numbers and letters indicating specific things unique to that manufacturer, such as tyre construction, tread compound etc. However the last four digits will always be the numbers quoting the date of manufacture.
The reasons this stamping is required legally is two-fold:
- It allows the tyre manufacturer to track when the tyre was made if there are issues when the tyre is in service. Tyres may be experiencing a specific problem that can then be traced to a week of manufacture and if necessary, the manufacturer can take whatever action is necessary – ensure factory procedures are revised to ensure it does not happen again or in worst case scenario, withdraw all tyres made in the problem week from service.
- If a tyre warranty adjustment is necessary the tyre date can have an input into how the warranty process is finalised.
And knowing what to look for allows anybody to know, for whatever reason, just when their tyres were manufactured.