What does the writing on the side of a tire mean?

Answer 1

It's an odd collection of both English and Metric measurements, which, together, tell you the size and applicabilty of a tire. Here's an example: P205 60 VR 15 The "P" means passenger car tire. The "205" means that the tire's tread (the part that touches the road) is 205 millimeters, or 20.5 centimeters wide. The "60" is the aspect ratio of the tire. That means that the sidewall (the part of the tire that extends from the car's wheel to the edge of the tread) is 60% of the width of the tire's tread. In our example case, then, the sidewall measures 12.3 cm from the wheel to the tread, measured radially. The "VR" is the speed rating. "V" rated tires are "safe" up to (I believe) 155 mph. "Z" tires are rated safe in excess of 155 mph. "H" rated tires are rated safe up to around 110 mph. I think. These three ratings comprise about 99% of what you're likely to see on a car. Finally, the "15" means that the tire will fit on a 15-inch wheel. This means that the diameter of the wheel is 15 inches. I don't know who came up with this strange mix of metric, English and ratio measurements, but it's been this way for many years. Hope that helps. Well, that's close. Actually, the first number, 205 in the above example, is not the width of the tread that touches the road, nor does it have anything to deal with anything touching the road. The first number is the OVERALL tire width, when inflated. Tread width is completely different. Oh, V rated tires are 149 MPH, not 155. S = 113 T = 119 H = 130 V = 149 Q = 99 used for winter tires The answer above is correct regard the 205. That means at it's widest point when inflated the tire is 205mm wide. Different manufactures have different tread widths with the same numbers. VBD