If you have a local AutoZone nearby, they have a good oil promotion running until the end of the month of October. Since my JCW only has 1,200 sweet miles on it and I want to abide by the warranty requirements, one of the MINI approved oils is Castrol Syntec Full Synthetic European formula 0W-30. Normally this oil sells at $6.99 per quart. Their special is 5 quarts + a filter. Since they didn't have a MINI filter, I had to pick any filter off the shelf and they did a return credit at checkout. The net result was an oil price of $3.86 per quart, or a $3.13 savings per quart.
I could be wrong about this but I think that refers to "German Castrol" as you'll see referenced many times elsewhere, like here: Welcome Fun to read for a while then your head starts to hurt. - Marc