In the tyre industry, there are many different types of tyres available. Each type has its own unique characteristics. These characteristics reflect the codes found on the sidewalls of the tyre. Understanding the codes will help you identify whether your current tyre needs replacement or not. Some of the codes are very simple to understand, while others may require a bit of research to get the correct information. We will cover all the codes in detail here.
You may have looked at your Car Tyres Reading and wondered what those strange markings mean. You probably haven’t thought about it before, but tyres contain lots of information. Some of it is useful, like when you need to check tyre pressure. Others aren’t. For example, there are many codes on the sidewalls of the tyres that tell you what size of the tyre you have
How to read tyres
When you buy tyres from the shop, they usually come with the manufacturer’s information printed on them. You can see this information when you check out online. If you get an invoice, the number is usually written next to the price tag. The information includes the tyre size, tread pattern, load index, speed rating, and a few other things. However, not all tyres have similar information. Some may say ‘XS’ instead of ‘S’. Others may have a different number to represent the load index. Most importantly, each tyre size comes with its own unique identification code.
There are many ways to identify a tyre size, but we’ll focus on the method that we mentioned earlier. When you see the tyre size, you should immediately write down the numbers 215 and 65. These two numbers indicate what kind of material the tyre gets made of.
There are two numbers here: 215 refers to the wheelbase and 65 refers to the overall width of the vehicle. These two numbers will help you figure out what kind of wheels the car will have. If the number is less than 150, then the car will have small wheels. If the number is greater than 150, then the wheels will be large in size.
We can also read the measurement of the sidewall in numbers like this: “P215/65R15? means that the tyre measures 215mm in width and 65mm in height. We can see this number again when we look at the dimensions of the sidewall. If you want to check the size of your tyres, just measure them using an old tape measure.
The aspect ratio of a tyre is the ratio of its width to its height. For example, if you have a tyre with a profile width of 200mm and a profile height of 100mm, then the aspect ratio is 2:1. If you have a tyre with an aspect ratio of 4:1, then the profile width will be 400mm and the profile height will be 200mm
Rim diameter is the measurement of the width of the wheel itself. If you were looking at the tyre size P215/65R14, 14, then the number after the slash is the rim diameter. So this tyre would fit a wheel with a 14mm diameter.
Load Index or the tyre load rating
Load Index or the tyre load rating shows how much weight a particular wheel can bear. It’s measured in kilograms per square inch (kg/in²) and indicates the maximum load the tyre can withstand when inflated to the specified air pressure. A higher number means that the tyre can carry a heavier load. For instance, P215/65R 15 95H means that the tyre is for a vehicle weighing 2,000 lbs (907 kg), and can withstand air pressure of 195 psi (13.8 bar).
Speed ratings indicate the maximum speed a tyre can handle safely. For example, if your car has a speed rating of 90H, then the tyre must not exceed 100Km/h before it starts to wear out. If you are going at a higher speed, say 120km/hr, the tyre will start wearing out after 6.5 minutes. You should buy tyres with matching speeds.
Maximum load rating
The maximum load rating is an important specification when choosing tyres. When you put a heavy vehicle on your car, you need a tyre that can handle the extra weight. A tyre that says ‘maximum load rating’ means that the tyre will hold the weight of what you need to put on the wheel. For example, if you are driving a truck and need a tyre with a maximum load rating of 8 tons, the tyre needs to be strong enough to hold 8 tonnes.
Tyre treadwear number
A tyre’s treadwear number is an indicator of how long it will take to wear out. Treadwear numbers range from 100 to 400. A tyre with a high treadwear number lasts longer than a tyre with a low treadwear number. A tyre with a treadwear number of 200 indicates that the tyre will last four times longer than a tyre with a 120 treadwear number.
Tyres Thatcham and tyre markings are not uniform across all tyre manufacturers. Some companies like MRF, Apollo and CEAT have similar patterns while others like Goodyear and Michelin have completely different patterns. So, if you’re looking to buy tyres online, you might need to go through multiple websites to get the best deal. Also, once you know what type of pattern is there, you can easily identify them even when they come in different sizes.