1. Any oil filter may be added if not originally equipped. Canister-type oil filters may be replaced with a spin-on type filter using a minimum amount of hardware and connecting lines.

2. Any oil or grease, including synthetic, is permitted.

3. Coolers and lines may be added for lubricating and hydraulic-type fluids (i.e. not fuel).

4. The installation of oil catch tanks or oil separators is allowed provided the function of the PCV system remains intact.

5. Cars with combustion chamber oil injection systems (such as those in rotary engines) may supplement the standard engine lubrication with additional oil supplied through the standard fuel delivery system.