I have a Mobil 1 sticker on my oil cap (the cap came from a Dodge Viper). I let it fight it out with my Castrol-loving intercooler cover.

 

Well, the API service rating (Industry standard) for the MINI oil says that it meets the new SL grading standard. Mobil 1 exceeds the SL grading....that's good enough for me; Mobil 1 it is. I'll take my chances

 

Just to back-up other posts in this thread, and caution others who think that Castrol Syntec is a 100% fully-synthetic motor oil.....

Well, do your research online before you decide to use Castrol.

Start here: CASTROL

They stopped using a fully synthetic base a few years ago, and now use a regular oil base to produce the 'synthetic' labled product.

They got taken to court over it, and argued symantics to allow the synthetic label to stay on their oil.

By all other synthetic manufacturers definitions, Castrol is no longer a fully synthetic oil.

Same price as synthetic, cheaper to produce than synthetic, still labeled as synthetic.

Not a good choice IMHO.

Chris.