The most basic information that you'll find on a tire's sidewall is related to its size. This is normally written as 185/65R15, for example, though you'll sometimes see "P" (for passenger cars) A typical tire size might read: P 205/65 R 15 92 H Here's what that means. P — This denotes a Passenger or P-metric tire built to U.S. standards. Here are other possible prefixes: LT is for a light truck. ST is for a special trailer. T is for temporary, usually indicating a spare tire. European-standard tires won't have a prefix letter at all. J - On some wheels, the letter 'J' might appear next to the wheel width, such as 16x7J. The letter J lets you know the shape of the wheels, and how the tire beads align with the wheels. J is commonly used for most passenger vehicles. Specialized vehicles may use other markings such as JJ, K, JK, B, P, A, D, S, T, or W. Finding your tire size is not difficult, you just need to know where to look! In today's article I'll explain tire sizes, how to find yours, what the numbers on a tire mean, and how to shop for and buy tires that will fit your car or truck. Let's start with the basics. The set of numbers straight after the tyre width refers to the thickness of the tyre wall (or aspect ratio), which is a percentage of the width. So, in this case, 55 would have a height equal to 55% of the tyre's width. This number is often referred to as the tyre profile. Tyre construction .

what does the size mean on a tire