Besides the "MINI" brand motor oil what brands and types are acceptable to use in a 2005 S

 

Castrol synthetic is what MINI uses.

 

you mean the oil in the fancy MINI bottles is actually Castrol??? thats funny, because when I went to buy the filter at mini he asked if I wanted the "MINI" oil I told him I would use castrol, he said thats not what we recommend. although the cap says "Use Castrol"
you gotta love those self proclamied experts at the parts counters

 

Yeah, the MINI branded oil is just Castrol.

 

what bout royal purple?

 

Go ahaid... there's no right or wrong oil and everyone has their preference. Anything you use, change it however often the manf. recommends and you'll be fine.