OCRS Tech Bulletin (July 26, 2019)
Hoosier Tire has informed the OCRS Sprint Car series that the 105 x 18.0 -15 (hard) tire is no longer being produced. The new hard tire compound that is now accepted for competition is the 105 x 18.0 -15 F85A tire. The price on these two tires is the same per Hoosier Tire.
Note: The 105 x 18.0 -15 will still be allowed for the balance of the 2019 racing season so teams may use up any inventory they may have. The tire rule has been updated in the rules section.