When you’re shopping for a batch of new tyres, take a moment to study what those markings on the sidewalls mean.
Tyre markings look like hieroglyphics, but can actually show a wealth of information about your tyres.
Most drivers will leave the mechanic to sort out the nitty-gritty, but it pays to know what you’re driving on.
Your tyres are the only things which contact the road, and having good ones is fundamental to safe driving, no matter how good a driver you are.
How inflated or deflated your tyres are is also crucial to getting better fuel economy and lessening tyre wear.
Here is a typical line of text you may find on your tyre sidewall:
Pirelli P Zero 225/55R17 97 W
Pirelli: Your brand of tyre, be it Bridgestone, Goodyear, Continental or Pirelli here.
P Zero: The model of tyre.
225: This refers to the width of the tyre in millimetres (mm), so for our example here, this tyre is 225mm.
55: This number is the tyre’s aspect ratio. The aspect ratio is the sidewall height expressed as a percentage of the tyre width. So in this case, the sidewall’s height is 55 percent that of the tyre’s width. The smaller this number is, the lower the sidewall height.
R: R refers to the tyre’s construction, radial in this case. Nearly all modern tyres have radial construction, which contributes to tyre longevity and better grip, among many benefits compared to cross-ply construction.
17: This number represents the inside diameter of the tyre, which is the size of your rim. So the next time you see this number, you can have a sizing contest with your friends to see who has the largest rims.
97: Refers to the tyre’s load index, the maximum load the tyre can carry when inflated to maximum (safe) pressure in kilograms (kg). This does not mean the tyre can carry 97kg; you have to use a table to convert 97 into actual load, which in this case is 730kg.
W: This is the tyre’s speed rating, the maximum speed which the tyre has been certified to carry a load safely. Similar to the load index above, the speed rating corresponds to the following speeds:
Q: 160 km/h
S: 180 km/h
T: 190 km/h
H: 210 km/h
V: 240 km/h
ZR: > 240 km/h
W: 270 km/h
Y: 300 km/h
Not applicable in Singapore (unfortunately) but applicable in other nations are snow markings on the tyres, the two winter markings being M+S and 3PMSF.
M+S simply means the tyre is a winter tyre, and 3PMSF (3 Peaks Mountain Snow Flake) are denoted with a little icon showing a three-peaked mountain, and are certified to handle difficult snow conditions.