“Decoding” the technical parameters on car tires
(Baonghean.vn) - When changing car tires, users often only care about tire size, manufacturer, price, and pay little attention to whether the technical parameters are suitable for their needs. Therefore, there have been many incidents related to tires such as tire explosions when running at high speeds, tires that are too noisy, and easy to be "cut by rocks"... Below are tire parameters that users need to pay attention to when choosing to buy.
Find service description features
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Not all tires have it, and if they do, it's usually located before and after the size name, which can be P, LT, ST, T, or C.
P: passenger vehicle tires
LT: light truck tire
ST: Special Trailer Tires
T: temporary replacement tire (Temporary)
C: commercial vehicle tires, heavy duty trucks
Understanding tire structure
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Most of these are marked with the letter R, which is located right after the tire profile. R stands for Radial construction, an industry standard for passenger cars, and is the most common tire type. Other vehicle types may be B, D, or E.
Rim diameter
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Measured in inches (1 inch = 25.4 mm); Example: P225/45R tire17The 91V will be mounted on a 17-inch rim. Some common rim diameters are 8, 10, 12, 13, 14, 15, 17, 18, 19, 20, 22, 23, 24, 26, and 28 (all in inches). These are all popular rim sizes for sedans, SUVs, minivans, vans, and light trucks.
Tire width and profile
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It is the series of letters and numbers that comes after the service specification and has a slash in the middle. The first three numbers are the tire width and are in millimeters. The width can be from 155 - 315. The example in the picture is 225 mm.
The next two numbers after the slash are the tire profile, which is the percentage of the tire's sidewall height compared to the tire's tread width and is usually between 55 - 75% for most cars. The example in the picture is 65%.
Tire profile is calculated: 205 mm x 65% = 133.3 mm.
Find the maximum allowable load index
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This number is particularly important as it indicates the load capacity of the tire, and the higher the number, the higher the load rating of the tire. This marking is not always just a number.
Never replace the original tire with a tire with a lower maximum load index, only use a tire with the same or higher load index. For example, if the tire in the photo is 82, the replacement tire must be the same type 82 or higher.
Find the maximum allowable speed index
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The number indicates how much load the tire can carry and how fast it can run. The letters indicate the speed limit for each specific tire type as follows:
P: 150 km/h (as example in picture)
Q: 160 km/h
S: 180 km/h
T: 190 km/h
U: 200 km/h
H: 210 km/h
V: 240 km/h
Z: over 240 km/h
Heat resistance index
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Indicates the resistance to high-speed heat in the inner part of the tire. The number can be A, B or C with A representing the highest heat resistance and C the lowest.
Tire pressure index
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Located on the lower rim of the tire, the maximum load index, the appropriate pressure index to maximize tire performance.
Safety edge - tire wear
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Tires should be replaced when the tread is worn down to the edge in the groove or the tire has many large cracks or uneven bulges on the side.
Everyone knows that using worn tires is especially dangerous. When the tread wears down to the edge in the groove, it is time to replace the tire. Using a bare tire not only makes it more likely to explode, but also increases the risk of losing traction in the rain.
Expiry
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Tires also have their own expiration date, so you should pay attention to this part to avoid buying car tires and then storing them in storage without using them. Although on the outside it may seem like the tire has no problem, in reality, when it is past its expiration date, the tire will lose all of its inherent features.
You can check the tire's expiration date by looking at the last 4 digits printed on the tire sidewall. For example, if the tire's last 4 digits are 1417, it means the tire was manufactured in the 14th week of 2017.
