Graffiti on the sidewall of the tires: What do the numbers mean?
Rim width
The first 3 digits indicate the total width of the tire in millimeters.
The symbol marked before the width on certain types indicates that it is a passenger car tire, sometimes denoted as P metric type loads. The significance of this is that the speed ratings (see below) change for P and P tires. tires no P.
Aspect ratio
The aspect ratio provides the ratio of the height to the width of the rim. In this particular example, the height of the tire is given as 60% of the total width of the tire.
In certain brands, the “/” is replaced by an “X”
Radial
This indicates the type of tire (in this case R stands for radial tires).
Having radial tires will technically provide better fuel economy for your vehicle while at the same time having less bulging effect than bias ply tires (which were the norm before radial tires were introduced)
* There is also the interesting fact that the steel wires in radial tires become magnetic with use and a significant alternating magnetic field is generated.
Wheel diameter
This will indicate the diameter of the wheel that the rim will fit (in this example, the rim will fit a 16-inch diameter rim)
Load index
The load index indicates the maximum load that a tire is certified to withstand at the maximum inflation pressure. It is strongly recommended to purchase a tire with a load index equal to or higher than the original vehicle tires. Depending on the load you intend to carry on your vehicle, you can decide the tire load index that best suits your needs by consulting the load index table.
Speed rating
The speed rating gives an indication of the maximum speed at which the tire will operate. This is an important factor to consider, as tires with a lower speed rating on a good car would definitely reduce its performance and create the risk of an accident.
Mud and snow
The final letters provide additional information about the tire. In the case of this example, the M and S indicate that the tire meets the standard required for a mud and snow tire. This combination is sometimes expressed as M + S, M / S, and M&S.
Besides M&S, there are other additional brands that can be found on different tires depending on their uses. Some of those brands are,
BSW: Black side wall
WSW: White side wall
OWL: White lettering scheme
TL: Tube Less
TT: Tube type (tires must be used with inner tubes)
LL: Light load
SL: Standard charge
SG: overload
VS: Commercial (light truck tires)
B: Belted Bias (motorcycle tires)
* Here you can check the load index and speed rating tables.
