What does 225/50/r18 mean for car tires?
2 Answers
The meaning of car tire 225/50r18 is that the tire has a cross-sectional width of 225mm, an aspect ratio of 50%, 'r' stands for radial tire, and a diameter of 18 inches. Below is an introduction to the location and method of checking tire specifications. Tire specification location: The original tire size of a car can be found in the owner's manual, on the border of the left front door, on the storage compartment door, or on the fuel tank cap. The tire specification information can also be found on the sidewall of the existing tire. Tire specification checking method: For example, if the tire specification is 195/65R1591V, '195' indicates the tire width is 195mm; '65' indicates that the tire's section height to width percentage is 65%, which is the aspect ratio; 'R' stands for the word RADIAL, meaning it is a radial tire; '15' indicates the rim diameter is 15 inches; '91' represents the load index; and 'V' indicates the tire's speed rating.
When I changed my tires, I also pondered over these numbers. 225 actually refers to the width of the tire's contact patch with the ground, measured in millimeters. This width directly affects grip and fuel consumption—wider tires provide more stability but increase fuel consumption. The number 50 represents the aspect ratio, which is the percentage of the tire's sidewall height relative to its width. A higher number means a thicker sidewall, resulting in a smoother ride over speed bumps, while a lower number offers better handling but increases the risk of bulging. The letter R stands for radial tire construction, which is now standard for most family cars. 18 indicates that the tire is designed to fit an 18-inch wheel. When selecting tires, it's crucial to refer to your vehicle's original specifications. Arbitrarily changing the size can cause issues during annual inspections and affect the accuracy of the speedometer.
