A tire can look almost new and still be old. Rubber ages with time, heat, sunlight and cold, whether the tire is rolling or sitting in a garage. That is why the date code is the first thing we look at on any used tire.
Where to find it
Look on the sidewall for the letters DOT followed by a string of letters and numbers. The date code is the last four digits of that string, often inside a small oval. It is usually on one side of the tire only, so if you cannot find it, check the other sidewall.
How to read it
The four digits are the week and the year the tire was made.
2319= week 23 of 20190822= week 8 of 20224517= week 45 of 2017
Tires made before 2000 used a three-digit code. If you see one of those, the tire is far too old to use, full stop.
How old is too old?
There is no single legal cut-off in Canada for tire age, and no one can predict the exact life of a specific tire from its date alone. What the industry does agree on is a range: most tire manufacturers recommend replacing tires somewhere between 6 and 10 years from the date of manufacture, regardless of tread. Some vehicle makers are stricter and point to six years. Check your owner's manual and the tire maker's guidance for your exact tire.
Our practical take when buying used:
- Under 5 years old: normal, judge the tire on tread and condition.
- 5 to 6 years old: look harder at the sidewalls for cracking, and pay less.
- Over 6 years old: we would think twice, especially for winter tires, which rely on soft rubber to grip on cold ice.
Why winter tires age faster in practice
Winter tires use a softer compound so they stay flexible through an Edmonton winter at -20 and below. As the rubber ages it hardens, and a hard winter tire with deep tread can grip worse than you expect. An older set stored in a hot shed or in direct sun ages faster still.
Check every tire in the set
Sellers sometimes mix tires from different years into one "set." The date codes should be close to each other. If one tire is three years older than the others, factor that into the price or skip it.
What we do
When you bring tires to our garage in Laurel, South Edmonton, we read the date code on each one before mounting. If a tire looks too old or the rubber is cracking, we will show you and talk it through before any work starts.