I have noticed a string of letters and numbers on the side of my tyres and I am wondering what they mean. Do I need to know or can I simply\y leave them for my mechanic to decode?
Johnson.
Hello Johnson, tyre information indicated on the side of your tyre is very useful and is provided by the tyre manufacturer to help you know which tyre is the right one for your car and driving conditions.
The information displayed on the sidewall usually includes tyre size; load and speed rating; . Tyre size is a combination of letters and numbers which can be found in the car user manual, driver door pillar, fuel flap or the tyre wall. For example a tyre may display this information on the sidewall 185/65 R15 94 H the first numbers declare the tyre width in millimeters.
Tyre width is crucial for vehicle handling and stability during high speed driving. The second set of numbers are the aspect ratio or percentage of the tyre width to height also called tyre profile. High performance cars usually have low profile tyres for better road holding and grip during high speed cornering.
Low profile tyres are uncomfortable to ride on and easy to damage when you hit a pothole at high speed.
The last set of numbers are the rim diameter which confirms that the tyre will fit on your rims. Load rating and speed rating are how much load the tyre can carry and the maximum weight it should carry at those speeds. For instance tyre load rating 94 and speed rating H means that the vehicle can carry a maximum load of 670 kgs at a speed of 210 KMH. The tyre side wall also displays the period the tyre was manufactured, this is usually near the initials DOT (Department of Transport) usually there is series of numbers: 22 24.
This means that that tyre was manufactured in the 22nd week of the year 2024. Any reputable tyre manufacturer will display the tyre manufacture date to help motorists know when the tyre has reached its lifespan of 5 years. Tyres expire after 5 years whether they have been kept in a store unused.
This is because rubber deteriorates with time making the tyre susceptible to bursting when exposed to heat under hard driving conditions.
