Tuesday, September 8, 2009

Know You Tire!

Have you guys ever wondered what are those numbers and characters on your tires are for? Lot of us doesn’t really care about it and leave it to our “trustworthy” mechanic to decide on that. If you take a look closer, you will see something below

175/70R13 82H

Firstly, the first 3 numbers i.e. 175. It shows the width of the tire. The wider it is, the better it is. And the following 2 numbers shows the height profile of tire. In this case, 70 means the height of the tire is 70% of tire width. However, in this case, the lower it gets, the better it is. Anything below 55% is called as “Low Profile” tire. I’m sure you have seen it on those luxury cars. Low profile tires give better handling and more stability in terms of road grip.

“R13” means the radius of the tire. In this case, it’s a 13 inch. The following 2 factors are one if the most important thing is selecting your next tire. The 2 numbers i.e 82 refers to load index of your tire. In this case, each tire with 82 LI allows [ referring to below chart ] the tire withstand maximum load of 475KG. So, if you have 4 tires [ Doh! ], that means 4 X 475KG = 1900KG. What does it means? You tires can only take max 1900KG of load which includes your total car weight, passengers and what ever it is in your trunk. For chassis weight you may refer to your car manual. It is very important not to overload your car because your tire may explode especially if it’s too old or getting too hot [ long distance driving etc ].

And the last character, “H” in this case means the max speed the tire can withstand. Lot of us never even knows that your tire can’t go more than certain speed even if your car can. “H” gives this car the maximum speed of 210KM. That’s pretty fast and I know for sure my car can't go faster than that. :P

Nevertheless, all above information is for a brand new tire. You have to understand that, the performance / stability / characteristic of your tire ware out as it’s getting old. Rotate your tire on every 10,000KM and keep it properly inflated. Change your tire when it’s time because tires without good tread causes you to loose your grip while on road, especially when it’s raining.

So, there you go. Now you know you tire pretty well. Go back and look at your tire and make sure you have the right one for you and your car.

Load Index Chart

Speed Index Chart

Reference : Wikipedia

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