To find an equivalent, you need to:
1. Check your supercharger's owner's manual: This will specify the exact type and viscosity of oil required. Look for terms like SAE viscosity (e.g., SAE 50) and any API or other specifications.
2. Use the specifications found in the manual to search for equivalent oils: Search online retailers (like Amazon, RockAuto, etc.) using the viscosity and specifications. Many manufacturers (like Royal Purple, Amsoil, etc.) make supercharger oils.
3. Contact the supercharger manufacturer directly: If you are still uncertain, contacting the manufacturer (e.g., Magnuson, Eaton) is the best way to ensure you use the correct oil. They can confirm compatible alternatives.
Simply looking for a "replacement" without knowing the specifications might lead to using an incompatible oil, which could damage your supercharger. Therefore, using the specifications is crucial.