What does R15 on tires mean?

[VanAaliyah]

R is the abbreviation of Radial, indicating that the tire has a radial structure; 15 is the outer diameter size of the rim, meaning it is 15 inches. Generally, the width of tires ranges between 145-285mm, with intervals of 10mm; while the aspect ratio of tires is between 30%-80%. Under normal circumstances, ordinary cars should not use tires with an aspect ratio greater than 75%, and luxury cars and high-performance sports cars are recommended to use tires with an aspect ratio less than 60%. Tires can be mainly classified by structure, tread pattern, type, and climate: 1. Tires classified by internal structure: can be divided into radial tires and bias tires. 2. Tires classified by surface tread pattern: can be divided into rib pattern tires, transverse pattern tires, mixed pattern tires, and off-road pattern tires. 3. Tires classified by vehicle type: can be divided into PC - passenger car tires, LT - light truck tires, TB - truck and bus tires, AG - agricultural vehicle tires, OTR - engineering vehicle tires, ID - industrial vehicle tires, AC - aircraft tires, MC - motorcycle tires. 4. Tires classified by climate: can be divided into winter snow tires, summer tires, and all-season tires.

[VonOlivia]

That's a very common tire size designation. The R15 on the tire actually refers to the wheel rim size. The R stands for radial tire construction, meaning the internal cord plies are arranged in a radial pattern. Over 90% of vehicles on the road today use this design. As for the 15, it indicates a 15-inch wheel diameter. I used to agonize over this number when changing tires because it directly affects tire and wheel compatibility. For example, you can't fit R16 tires on factory R15 wheels - they'd rub against the wheel arches. When selecting tires, you also need to consider number combinations like 195/55 at the front, where the first number indicates tread width and the second is the aspect ratio. Many family cars like the Fit and Corolla now use R15 tires, striking a good balance between comfort and cost.

[OmarRose]

Speaking of tire sizes, I have some personal experience. R15 indicates a tire specification suitable for 15-inch rims. The letter R denotes a radial tire structure, where the internal cords are arranged radially, making it more fuel-efficient and durable compared to bias-ply tires. The number 15 refers to the rim diameter in inches. Getting this size wrong during a tire change is a common fear. Last year, when helping my cousin change tires, we encountered this issue—he had 14-inch rims but bought 15-inch tires, only realizing they didn’t fit during installation. When selecting tires, you also need to consider parameters like width and aspect ratio, such as the full specification 195/65R15. Remember, the rim size is marked next to the small dot symbol, and it’s also indicated on the spare tire.

[VanEmily]

R15 is a crucial part of tire specifications, indicating a rim diameter of 15 inches. The 'R' stands for radial construction, a design that makes tires more wear-resistant with minimal deformation. Common specifications like 185/65R15 break down as follows: the first part (185) represents the tire width in millimeters, and 65 is the aspect ratio percentage. When selecting tires, R15 must strictly match the wheel hub size; otherwise, installation will be impossible. Compact cars like the POLO often use R15 tires due to their lightweight and low rolling resistance, offering better fuel efficiency than larger rims. Some older vehicles may feature letters like 'S' or 'T' to denote speed ratings, where an 'H' rating allows speeds up to 210 km/h. It's recommended to prioritize original factory sizes when replacing tires, and any size modifications require registration with the vehicle management office.