Difficulties relating to raw material supply, electricity availability, and transport restrictions have greatly impacted the availability of the Toyo Proxes RA-1 tire which is the specified tire for many NASA classes. As such, NASA will be removing the requirement to use the Toyo Proxes RA-1 from the American Iron, Honda Challenge, and Spec 944 classes beginning on May 1, 2011 and will allow any DOT-approved R compound tire. Spec Tire classes will be handled on a case-by-case basis, so please keep informed by visiting the www.nasaproracing.com for any new information if and when it's posted or by visiting your class section on the www.nasaforums.com. NASA will be sure to post any new information when it's available.