195 55r15意思

"195 55R15" is a tire size designation, where:

• "195" refers to the tire's width in millimeters. This is the width of the tire from one sidewall to the other when it's mounted and ready to be used.
• "55" is the aspect ratio, which is the percentage of the tire's width that the tire's sidewall height is. In this case, the sidewall height is 55% of 195mm.
• "R" stands for "radial," which indicates the construction method of the tire. Most tires sold today are radial, meaning the tire's ply cords extend radially across the tire from bead to bead.
• "15" is the wheel diameter in inches. This is the size of the wheel that the tire is designed to fit.

So, a tire size of 195/55R15 means the tire is 195 millimeters wide, the sidewall height is 55% of that width, the tire is constructed with radial plies, and it is designed to fit a 15-inch wheel.