Does castrol 10w-30 have a shelf life?

Yes, Castrol 10W-30, like most motor oils, has a shelf life. Generally, unopened bottles can last about 5 years if stored in a cool, dry place away from direct sunlight. Once opened, it’s best to use the oil within a year for optimal performance, as exposure to air and contaminants can degrade its quality. Always check for any changes in appearance or smell before use.