Interesting thing about Castrol: they don't make a drop of oil. They buy from outfits like Exxon and put in their own additives. They do oil and additive research to arrive at an add-pack.
that is the way amsoil started. buying jet engine lube and putting their additives in it.
You mean they are making their own syn stocks and not buying them now ?
Ben
Back in the 1960s, I had a mechanic friend in upstate NY. He says he put some Castrol outside one winter. Tried to pour it the next day. It wouldn't pour. Normally, canned oil is pour depressed to pour at -40 F. Guess this wasn't.
That may well depend on the grade or weight of the oil which back in the 60's was probably straight weight 30. It could have been -20 out as well. This test can be performed by anyone whether your mechanical or not.