I need to do an oil change and would like to put synthetic oil in the GS. I have 2 liters of Castrol synthetic, they are unopened but about 10 years old.
Does anyone know if the age of unused old is an issue towards its effectiveness? :dunno_white:
Is it ok to mix old Castrol synthetic with new Castrol synthetic? :dunno_white:
I'm sure a good deal has changed in the last ten years. I think the shelf life really depends on the environment you kept it is, temperature changes, moisture. I would think that it is safe to say that the 10 year old oil is past its shelf life. this website: http://www.carbibles.com/engineoil_bible.html says that engine oil has a shelf life of abou 3 years.
I'd personally jsut go for new oil.