Sunday, November 1, 2009

Understanding your tyres (can be quite tiring)...

How to check Car manufacturing date

Actually it's very simple...

Look for the 4 digit code on the tyre. It represents the week and the year the tyre was manufactured, i.e. wwyy.

Let's say the digit on my tyre is 3808, that means, it's manufactured on the 38th week of 2008.

The longer the tyres are kept, the harder the rubber will become. :)


How to decipher the codes on your tyres:

Since there are lots of codes on a tyre, we would all wonder what all of these codes mean. Well, I suppose since we're not tyre shop owners, I think it's just suffice to know the model and profile of your tyre and here's something I found from carbibles.com.


KeyTyre Marking Description
AManufacturers or brand name, and commercial name or identity.
BTyre size, construction and speed rating designations. Tubeless designates a tyre which requires no inner tube. See tyre sizes and speed ratings below. DIN-type tyre marking also has the load index encoded in it. These go from a load index of 50 (190kg) up to an index of 169 (5800kg).
CDenotes type of car tyre construction.
D M&S denotes a car tyre designed for mud and snow. Reinforced marking only where applicable.
E Pressure marking requirement.
FECE (not EEC) type approval mark and number.
GNorth American Dept of Transport compliance symbols and identification numbers.
H Country of manufacture.


Tyre Size Notations

When you change tyres, you will need to know which type of tyre that you need to fit your rims. This is done by refering to the funny code that comes under the B marking. To decipher the funny code that signifies your tyre size, refer the table below (I will use my own tyres,195/55/R15,as a guide):

19555R15
Section widthAspect ratioTyre Constuction. R for RadialRim diameter


Tyre Size NotationDescription
Section WidthThis is the width in mm of the tyre from sidewall to sidewall when it's unstressed and you're looking at it head on (or top-down).
Aspect Ratio

This is the ratio of the height of the tyre sidewall, (section height), expressed as a percentage of the width.In this case, 55% of 195mm is 107.25mm - the section height.

Higher aspect ratios provide better comfort.

High performance tyres usually have a lower aspect ratio than other tires. This is because tyres with a lower aspect ratio provide better lateral stability. When a car goes around a turn lateral forces are generated and the tyre must resist these forces. Tyres with a lower profile have shorter, stiffer sidewalls so they resist cornering forces better.

Tyre Construction

"R" tells you that the tyre is of a radial construction. There are 2 types of tyre contruction, Bias/Cross-ply Construction and Radial Construction.

Radial tyres are almost used on almost all the world's passenger vehicles now (for the past 20 years or so) as they are more resistance to tear and provide higher performance and better fuel economy.

Rim DiameterThis is the diameter in inches of the rim of the wheel that the tyre has been designed to fit on.


Well, now you know at least something about tyres. Change them every two years or when you noticed the tread have worn off. Here's signing off in support of better safety on the road. Yawn.. this is tiring... hahaha.

New Tyres for the tired...

My tyres are way overdue. The old faithful Yokohama S306 have served me well. Well, for that profile 195/55/R15, it really served me well with the quiet and comfortable soft feeling that I get when I drive around. And it's really steady for a tyre that had been sitting in the storeroom for 2 years.

My tyres dated 2005... I bought them in 2007 but people tell me that tyres harden even when you don't use them. Since I am a low usage and safe driver, I decided to ignore the 2 years shelf life and just continue with the recommended on-the-road tyre life of 2 years (Actually, also because I wanted to save cost on changing tyres as it doesn't feel "monetary-correct" to change brand new tyres when I first got the car). So my tyres are actually 4 years old now, way overdue... And after much nagging from dear old friends of mine (thank you so much for caring for my safety... ), I decided to change them yesterday.

The tyre changing ritual started with the inevitable price checking... People (friends and car forums) tell me that Klang can offer very competitive prices for all kinds of brands. They tell me that depending on the type of tyre I get, I can save up to RM50 per tyre and that savings can cover the petrol cost of going all the way down there and also even cover a bak-kut-teh meal or two.... Hmmm very tempting... especially the bak-kut-teh bit.. :)hahaha...

Anyway, one good guy told me that there's a reputable tyre shop in Maluri, Cheras which could match the price ... maybe slightly more expensive by RM5 or RM10.

Prices quoted by Klang was Yokohama - RM180, Falken - RM175, Bridgestone - RM155, Michelin - RM200.

Price at Cheras was Falken - RM175 by cash, RM180 by credit card.

And I thought, well, why not, since it's more convenient for me to do my chores during lunch time than during weekends. And so to Cheras we went on that fine Friday as most of us have more flexible lunch time on Fridays.

It was an eventful Friday. Most of the guys just wanted a change of taste when it comes to lunch, so we all packed ourselves into 2 cars and headed to the town which is famous for its seafood noodles. Tyres were changed in 1 hour. The price came with free balancing, free alignment and free checking of the year of the tyres (my friend actually went to check the year the tyres were made and ensured that I got the latest tyres... :)) Will let you know how to check the age of the tyres in my next installment... meanwhile, I have to go wash my car and get some pictures.. :)

Thanks guys. Didn't bring enough cash the other day for the seafood noodles... next meal on me.. :)