What does 225/45r18 mean?

[DiAndrew]

225 represents the tire's section width of 225 millimeters, 45 represents the aspect ratio, which is the percentage of the tire's section height divided by its width, R stands for radial tire, and 18 indicates the rim diameter of 18 inches. Here is an introduction to tires: 1. Types of tires: The international standard tire code expresses the section width and aspect ratio as a percentage in millimeters. It is followed by: tire type code, rim diameter (in inches), load index (permissible load capacity code), and permissible speed code. 2. The functions of tires are: to transmit driving force, braking force, and steering force to achieve vehicle operation; to support vehicle loads; to reduce and absorb vibrations and impact forces during driving, avoiding severe vibrations that could damage vehicle components. 3. Tire maintenance methods include: regularly cleaning stones from tire treads; minimizing exposure to sunlight; promptly checking tire pressure; paying attention to suspension maintenance; periodically inspecting front wheel alignment; and being mindful of driving habits.