Mixing fully and semi synthetic oil...

[ArtfulHussy]

Uhm.. I made a boob. I was cleaning out the garage and noticed I had three part full bottles of 5w30 so I thought I would be good and condense them all into one bottle. It wasn't until after that I realised that one of them was part synthetic and two of them were fully synthetic. Have I just wrecked the lot or will it be okay?

 

[Frank]

Will be OK.

 

[Dal]

Semi synthetic is basically fully synthetic with extra additives.

Semi synthetic oils are cheaper than fully synthetic as they are a mixture of synthetic and mineral oil. Engines requiring semi synthetic oil must use at least semi synthetic oil (not mineral oil) but may benefit from upgrading to fully synthetic oil for increased protection and performance.

As Frank says, it'll be fine.