Street Tire Multiplier

hoosier-vs-bfgUPDATE: At the February 2014 club meeting members voted to remove the Street Tire Multiplier from the “Stock” classes (now known as Street classes).  They also voted to remove it from the PAX classes.  But it can still be used for all non-stock classes.

At the March 2013 club meeting the SSSCC voted in a new Street Tire Multiplier rule using a 0.980 multiplier.   The issue was that many of the Sports Car Club of America (SCCA) rules allowed DOT legal r-compound race tires, and they are expensive.  To compensate the SSSCC added local Street Tire classes for those people who didn’t want to buy race tires.  But as a result, the standard classes (S1, S2, NS2, etc…) were decreasing in size.  Also, drivers in the Street Tire classes weren’t able to compete fairly for the Top Pax award.   As a result, it was decided that the club would eliminate the Street Tire class and the Ladies Street Tire class and start using a Street Tire multiplier for all classes. Drivers now have the option to run on either Street Tires or whatever race tire that’s legal for the class they are running in.

What qualifies for street tires?  Currently, any tire that has a tread wear rating of 140 or greater.  Popular tires include the BFG Rival, Dunlop Z2, Bridgestone RE-11A, Toyo R1R, and Hankook RS-3.  What qualifies for race tires?  In the Stock and Street Prepared classes you can choose from any of the DOT-legal tires.  Popular tires include the Hoosier A6, BFG R1-S and Kumho V710.   If you’re running in one of the Prepared or Modified classes, you can run full racing slicks.  Hoosier, Goodyear and Avon all make popular choices.

For example, if you’re running a Acura Integra in DSP, you can either run street tires with the street tire multiplier, or race tires.   Here’s how the math would work:

street-tire-multiplier-math-2014