The 2025 season will be the last year that ORC Stock Rods will run on 13” wheels.  From the start of 2026, the formula will progress to 15” wheels.

For the 2025 season, the following regulations will apply to tyres:

On the driving axle, only the HiFly HF201 185/70R13 tyre may be used.

On the non-driving axle, either the  HiFly HF201 185/70R13 or the Yokohama A021R tyre may be used.  This will be reviewed by 1 May 2025.