The car tyre is marked with various information on its wall, including the tyre size, load rating, speed limit, place of manufacture, time of manufacture, etc.
For example, the tyres originally come with Toyota Avanza 1.5 has the designation of 185/65R15 88S. This denotes the tire has:
- section width of 185mm
- aspect ratio of 65, which is calculated by its (height/width)
- "R" for radial construction
- rim diameter of 15 inches
- load rating of 88, which can carry maximum weight of 560kg
- speed rating "S", which the maximum safe speed is 180km/h
There is also a 4-digit batch number, or a code longer than 4-digit and the last 4 digits are numeric. The first two digits are the week of manufacture, and the last two digits are the year of manufacture. For example, a batch number of "1007" indicates the tyre was manufactured on the 10th week of year 2007.
The rubber of the tyre will degrade over time no matter it is being used or not. It is recommended to change tyres at most 6 years from their manufacture time. When you purchase new tyres, ensure that the tyres are manufactured less than 1 year so that you can use them for a longer time.