The code has grown in complexity over the years, as is evident from the mix of SI and USC units, and ad-hoc extensions to lettering and numbering schemes. Sometimes the inner sidewall contains information not included on the outer sidewall, and vice versa. This code specifies the dimensions of the tire, and some of its key limitations, such as load-bearing ability, and maximum speed. Alphanumeric code specifying tire sizes and limitsĪssorted new car tires with a variety of tread patterns and different sizesĪutomotive tires are described by an alphanumeric tire code (in North American English) or tyre code (in Commonwealth English), which is generally molded into the sidewall of the tire.
