Purchasing tires of a specific size on eBay is done by looking for certain codes within the listings. The number codes found on some of the listings contain the sizes and tire types within them, making them easier to locate for those that know the codes.
Tires are listed with strings of numbers and letters that consist of measurements and designations. The tire types are P, T, ST and C, plus LT at the end or beginning or a designation. These designations indicate passenger, spare, special trailer service and Euro tires, as well as oversized light truck and ordinary light truck, respectively. After this service type is listed, the section width and sidewall aspect ratio are listed as number measurements. Then the internal construction lettering, the speed rating, tire and wheel diameter and service description are included. For instance, a tire code of P265/70R17 91S is a passenger tire of 265 millimeters section width, 70 percent sidewall aspect ratio, radial construction, 17 inch rim diameter and a load index of 91 and a speed rating of S.
Some exceptions exist within tire codes, such as the Z speed rating. This speed rating is found before the internal construction code, such as in P265/70ZR17.
It's possible to narrow down the search before searching for a specific tire code by using the eBay Tire Center and selecting the appropriate make and model of vehicle to filter out incompatible tire types. Further filters, such as warranty and location, help to narrow the search further.