Tires - things not everyone knows

Tires are important parts of a vehicle, so it is important to pay attention to the manufacturer's recommendations, care, maintenance and regular tire replacement.

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Tires (casings) are one of the components that make up a car, they are quite simple, few people pay attention to but have extremely important meaning. It can be said that those small tires are carrying the safety of your whole family on their backs. Many car users have the idea that tires are not important, when they feel worn out, they just replace them.

Most vehicle owners take their vehicles to the mechanic for tire changes, and tire selection is often left to the mechanic. However, having a basic knowledge of tire terminology will help avoid the situation of “matching one man’s beard to another woman’s chin”, or tires that are not suitable for the vehicle, or the conditions of use.

On the tire sidewall, there are often many letters and numbers that show the size and type of tire. For example, on the tire there is the line, number P215/65R17, the letter P stands for "Passenger Vehicle", which means a car with 7 seats or less. If the letter P is replaced by LT, it means the tire is for light off-road vehicles (Light Truck). If the letter P is replaced by the letter C (Commercial), this is a type of tire specifically for commercial delivery vehicles or heavy trucks.

In terms of numbers, 215 is the width of the tire in millimeters, while the second number, 65, represents the ratio of the tire's sidewall height to its width. In this case, the sidewall is 65% of the tire's 215 mm width.

The letter R stands for Radial, which represents a radial tire structure, to distinguish it from the Bias type. Radial tires are often used for passenger cars because they are suitable for all types of roads, while Bias tires are often used for off-road vehicles. In terms of driving feel and fuel efficiency, Bias tires are “inferior” to Radial tires.

The last number, 17, refers to the inch diameter of the rim. One discrepancy here is the unit of measurement. While tire sizes around the world are measured in metric units, rim diameters are measured in inches.

When buying tires, you need to know the tire size of your vehicle. The most important thing to note is to choose a tire size that is close to the original tire width of the vehicle. If you replace it with a tire that is too large, it can affect the suspension components. Using a tire that is too small will not be able to handle the load and will reduce the vehicle's traction, causing the anti-lock braking system (ABS) to work less effectively. It is best to use the original size or the manufacturer's instructions.

The ratio between the height of the tire's sidewall and the width of the tire is also important. A tire with a 50-ratio has a lower sidewall than a 65-ratio tire, which gives more steering precision but reduces the ride comfort when driving on bumpy roads. The only time to change this ratio is in the winter in cold countries, and you should also change the diameter of the wheel rim. Using winter tires with a higher sidewall ratio will help the car ride smoother in the winter.

However, a taller sidewall also means a taller tire, which may not fit over the fender. In this case, you can change the rim size down, say from 17 to 16 inches, so that the wheel size is basically the same, but the ride is smoother.

In addition to the basic information above, the tire sidewall also has many other symbols, such as maximum load, maximum tire pressure and maximum safe speed. Information about load and pressure is quite easy to understand, while speed is specified by code. Specifically, the letter T indicates the maximum allowable speed of the tire is 190 km/h; the letter H corresponds to 210 km/h; the letter V is 240 km/h; and the letter W is 270 km/h. Z tires are not internationally standardized and depend on each manufacturer, but at least can withstand the same maximum speed as V tires. Normally, only T tires are enough to run on the highway.

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According to VNE