| 1 |
All 2WD drive cars up to and including 1400cc |
| 2 |
All 2WD drive cars from 1401cc up to and including 1650cc, having not more than 2 valves per cylinder |
| 3 |
All 2WD drive cars from 1401cc up to and including 1650cc, having more than 2 valves per cylinder |
| 4 |
All 2WD drive cars from 1651cc up to and including 2100cc, having not more than 2 valves per cylinder |
| 5 |
All 2WD drive cars from 1651cc up to and including 2100cc, having more than 2 valves per cylinder |
| 6 |
All 2WD drive above 2100cc |