Ever wondered, what do those number and letters on your tire’s sidewall actually mean? Let us understand what these numbers actually mean so that next time you can really make a decision what you really want for your Car when it comes to Car Tires.

Let us suppose tire size says P235/75 R15 87V. Firstly, that “P” denotes a passenger car, certain to standards within USA , if it contains no alphabet then it is probably according to standards within Europe, both may have different load capacities, “LT” denotes it is for Light trucks.

The next three digits denote the tire width, like how wide it is when measured from sidewall to sidewall in millimeters. So, it denotes the width is 235 millimeter. The next two digits denote the aspect ratio. The aspect ratio of a tire is defined as ratio of height of the cross-section of the tire to that of width, so taken into account 75 means the height is 75% of the tire’s width. If the aspect ratio is bigger, the sidewall of the tire is bigger. But usually the high performance tires have low aspect ratio. It is because of the fact that they provide lateral stability. Tires with low aspect ratio have shorter and stiffer sidewall so they can face the force against them better.

The Next Alphabet “R” denotes it is Radial in nature that means the layers are radially across the whole tire. The next numbers denotes the wheel it is intended to fit in. So, 15 denote the tire is going to fit in 15” wheel diameter.

Next digits 87 denote the load index. Load Index is basically the table which tells us about how much weight, a tire can handle without any difficulty. If the load exceeds that limit, it can lead to steering instability and even rupture. Sometimes they use special Symbols like RF or XL which stands for Reinforced and Extra Load respectively.  Finally, the Letter “V” denotes the Speed Symbol. The maximum speed the car can attain, with full load is described in this Symbol. Every Symbol has its own Speed Range  There are some more symbols for different speed limits.

 Speed Rating Symbols Speed Category J Upto 62mph (100 Km/h) N Upto 87mph (140 Km/h) P Upto 93mph (150 Km/h) S Upto 112mph (180 Km/h) H Upto 130mph (210 Km/h) V Upto 149mph (240 Km/h) W Upto 168mph (270 Km/h) Z Over 149mph (240 Km/h)