Minimum Tyre compound for Sprintcar left rear tyres have come into effect as of the 1st of July 2012. As per the SCCA Racing Rules, Regulations and Specificaions book, this ruling was in the 2011 rulebook giving competitors notice of the change, see page 37 of the 2011 rule book. This trye ruling only applies to the SCCA Sprintcar specifications, not the Australian Wingless Sprints that will still have an open tyre make and compound.

The Sprintcar Tyre rule for Left rear and right rear tyres as per the 2011 book reads: Page 37 (iv) Tyres
(a) All cars must use tyres that are in good condition.

(b) Right Rear tyre minimum compound equivalent to American Racer MC1, Hoosier RD12, or Goodyear M200.

(c) From the 1st of July 2012, the minimum tyre compound allowed for the Left Rear tyre is a RD12 Hoosier, SD33 American Racer, or a 200 Goodyear.

No other brand of tyre is to be used in this position from this date without first submitting the tyre to the SCCA technical committee for evaluation.