Silkolene Castorene R50S Castor Based, Synthetic Enhanced, Racing Oil Castorene R40S & R50S racing oils are castor oil based blends incorporating synthetic lubricants and additives which enhance the castor oil’s naturally high film strength and resistance to seizure. This enhancement represents a significant advance in lubricants containing vegetable oil and minimises the risk of thickening or lacquer formation.
NOTE: These are not detergent grades, and more frequent oil changes are required than with additive treated mineral oils. Castorene R40S & R50S must not be mixed with mineral oils.