If you take a close look at the sidewall of your car tire, you will notice that there are many alphabets and numbers molded on it and you will probably be wondering what exactly do they all mean. As a layman, none of that makes any sense but as a tire manufacturer and dealer, all that is valuable information about the tire.
There are a number of key pieces of information you need to know about your tires. As the owner of a vehicle, it is important to understand what some of that means especially when it comes to changing to a set of new tires. Knowing and understanding that the tire dealer has fitted the correct size recommended for your make and model is crucial.
Tire size and service description
- Section width is measured in mm. This is referring to the width dimension of the tire, the part of the tire that is in contact with the road.
- Aspect ratio is measured as a percentage of the section width. What this actually means is that the height of the tire is only a fraction of the section width. In this example, the height is only 45% of the 235 mm section width. Another way of referring to such kind of dimension is that it is a 45 series tire.
- Rim size is usually measured in inches. This is referring to the diameter of the metal rim that this tire is suitable. The example in this case is that this tire is suitable to be fitted on a 17 inches rim.
- The load index rating on a tire indicates the load carrying capacity of the tire in kilograms. As in this example, a 97 load index tire will be able to take a load of 720 kilograms of weight when inflated to the recommended pressure. Always adhere to the manufacturers load rating as indicated on the original set of tires.
- The speed index rating is denoted in an alphabet form usually next to the load index number. The `W` rating in this case refers to a tyre that can be used up to a maximum speed of 270 Kmh. Again , stick to vehicle manufacturers recommendation.
Age of the tire
When buying a new set, it is important for us to know the production date of the tire. With this information, we will be able to tell the age of the tire and how long the tire has been on the shelf of the manufacturer or dealer. Tires are subject to deterioration over time and as a general rule, we should not be purchasing a set that is older than 3 years from the date of production.
For example, the production number on this tire is indicated as 4208. This means that the tyre was produced on the 42nd week of the year 2008. Based on this information, we can tell the age of the tyre. Once in use, a tire can be used up to 6-8 years, of course depending on the tread depth available. Tires older than 8 years should never be used even if it has the full tread depth.
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