[split] My BMW 540i makeover thread - Engine flush discussion

[KevSTer]

You can put a Diesel engine oil into a Petrol engine but you cant do it the other way round. Diesel engine oil has better lubricating properties due to it's shear properties in the oil meaning it's less prone to viscosity breakdown. Diesel engine oil also has more detergent's so it will keep the engine cleaner or in Don's case clean it out progresively.

Flush can loosen the particles you dont want meaning it could block the oil pick up and attack oil seal's and the car could start to leak oil after a while.