The PAX index was developed by Rick Ruth and reflects study of results from well over 500 nationwide Solo events. The below information is sourced from the official PAX webpage.
| Category | Class | Multiplier (2005) | Multiplier (2004) | Difference |
|---|---|---|---|---|
| Stock | A Stock | 0.828 | 0.828 | 0 |
| Stock | B Stock | 0.821 | 0.826 | -0.005 |
| Stock | C Stock | 0.810 | 0.811 | -0.001 |
| Stock | D Stock | 0.796 | 0.794 | 0.002 |
| Stock | E Stock | 0.806 | 0.804 | 0.002 |
| Stock | F Stock | 0.805 | 0.803 | 0.002 |
| Stock | G Stock | 0.782 | 0.781 | 0.001 |
| Stock | H Stock | 0.777 | 0.776 | 0.001 |
| Stock | Super Stock | 0.837 | 0.836 | 0.001 |
| Street Touring | Street Touring Sport 2 | 0.803 | 0.810 | -0.007 |
| Street Touring | Street Touring Sport | 0.799 | 0.791 | 0.008 |
| Street Touring | Street Touring Ultra | 0.818 | 0.827 | -0.009 |
| Street Touring | Street Touring Xtreme | 0.802 | 0.795 | 0.007 |
| Street Prepared | A Street Prepared | 0.850 | 0.848 | 0.002 |
| Street Prepared | B Street Prepared | 0.839 | 0.839 | 0 |
| Street Prepared | C Street Prepared | 0.838 | 0.837 | 0.001 |
| Street Prepared | D Street Prepared | 0.822 | 0.819 | 0.003 |
| Street Prepared | E Street Prepared | 0.826 | 0.824 | 0.002 |
| Street Prepared | F Street Prepared | 0.811 | 0.813 | -0.002 |
| Street Modified | Street Modified | 0.842 | 0.838 | 0.004 |
| Street Modified | Street Modified 2 | 0.852 | 0.849 | 0.003 |
| Prepared | A Prepared | 0.865 | 0.868 | -0.003 |
| Prepared | B Prepared | 0.861 | 0.863 | -0.002 |
| Prepared | C Prepared | 0.855 | 0.854 | 0.001 |
| Prepared | D Prepared | 0.844 | 0.844 | 0 |
| Prepared | E Prepared | 0.858 | 0.861 | -0.003 |
| Prepared | F Prepared | 0.862 | 0.862 | 0 |
| Modified | A Modified | 1.000 | 1.000 | 0 |
| Modified | B Modified | 0.942 | 0.945 | -0.003 |
| Modified | C Modified | 0.908 | 0.913 | -0.005 |
| Modified | D Modified | 0.879 | 0.886 | -0.007 |
| Modified | E Modified | 0.886 | 0.894 | -0.008 |
| Modified | F Modified | 0.884 | 0.889 | -0.005 |
| Formula | Formula SAE | 0.948 | 0.960 | -0.012 |
| Formula | Formula Junior 1 | 0.781 | 0.785 | -0.004 |
| Formula | Formula Junior 2 | 0.797 | 0.792 | 0.005 |
| Formula | Formula Junior 3 | 0.823 | 0.825 | -0.002 |
| Formula | Formula Junior 4 | 0.832 | 0.834 | -0.002 |
| Formula | Formula 125 | 0.939 | 0.938 | 0.001 |
| Category | Class | Multiplier (2005) | Multiplier (2004) | Difference |
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