Castrol Power 1 4T 10W-40 Engine Oil Castrol Power 1 oils have been developed with cutting- edge formulation technology, underpinned by more than 100 years' experience in motorcycle lubrication.For four stroke engines, Castrol Power 1 4T 10W-40 with Power Release Technology™ optimises friction which in return provides motorcycle enthusiasts with a superior acceleration at the twist of the throttle. The Semi- synthetic premium quality oil is designed for high performance motorcycles.Semi-synthetic. Specifications: API SN; JASO MA-2. 4L Bottle.