What does 235/55r18 mean for tires?
2 Answers
23555r18 means: 235 indicates the tire's cross-sectional width of 235mm; 55 represents the aspect ratio, which is the percentage of the tire's cross-sectional height divided by the tire width. A higher value means a thicker tire, resulting in lower maneuverability but increased comfort; r stands for the tire type, radial tire, and 18 indicates the rim diameter of 18 inches. Below is relevant information: 1. Tire marking: Tire marking refers to the international standard tire code, usually located on the sidewall of the tire, indicating the section width and aspect ratio as a percentage, in mm. It includes the tire type, rim diameter (in inches), followed by the load index and speed rating. 2. Service life: Since tires have a limited service life, paying attention to the production date is also very important. The production date is generally on the outer side of the tire, consisting of four digits: the first two digits represent the week number, and the last two digits indicate the production year.
I recently bought a new car, and the tires are marked with 235/55R18. At first, I was quite confused, but later I figured out the secret behind these numbers. 235 refers to the width of the tire in millimeters, meaning the part of the tire that contacts the ground is 235mm wide. The wider the tire, the more stable the car feels, especially when changing lanes on the highway, giving a much more secure feeling. The number 55 is called the aspect ratio, which calculates the height as a percentage of the width. A 55% ratio means the tire sidewall is relatively thick, providing good cushioning when going over speed bumps or rough roads, resulting in less bumpiness and a more comfortable ride. The 'R' stands for radial tire, which is used by most cars nowadays, being more durable than the older types. 18 is the diameter of the wheel rim in inches. An 18-inch size is moderate, not taking up too much interior space, and makes it easier to find replacement parts when changing tires. For my daily city driving, this size combines safety and comfort, and the cost of tire replacement isn’t too high. Learning more about maintenance can help extend the lifespan of the tires.
