Clarification Maximum Allowable Wheel Rim and Tire Section Widths
#29482 from Gregg Campbell · No action required · Minutes (2020-12 Fastrack)
Thank you for your letter. Wider wheels were allowed in IT classes where the existing wheel sizes and tire offerings are or were
becoming rare, and similar but common wheel sizes existed (i.e. 14 or 15x6 to 15x7). In order to limit the overall performance
benefit of this allowance over existing wheels, the maximum tire size was set lower on the newly allowed (larger) widths than on
the legacy (smaller) width wheels. Wheel widths are stated as "MAX" meaning that the tire section limits are for all wheels up to
that width but no larger (e.g a 6.1" wide wheel would be treated as a 7" wheel in ITB).