Reply to thread

Message: <blockquote data-quote="Hyaenidae" data-source="post: 30469448" data-attributes="member: 530392">Not really,Multigrade oils have base oil + viscosity modifiers. Think of viscosity modifiers as a coiled spring of sortsSo in a 10W30 oil the base oil has a viscosity of SAE10 when the engine is cold, viscosity modifiers are fully curled upAs the engine warms up the viscosity modifiers unfurl themselves, like coiled springs getting uncoiled. At operating temperature, that unfurled viscosity modifiers "thicken" the oil to act like SAE 30 oil, even as the SAE 10 base oil "thins".As the engine cools down the viscosity modifiers curls again, making the oil "thinner" down to the viscosity of the base oil which is SAE10.So essentially a 10W30 multigrade oil has a viscosity of SAE10 when the engine is cold and a viscosity of SAE30 when the engine is at operating temperature.</blockquote>

Top Bottom