I change my oil every 5,000 miles with BMW/MINI's OEM Full Synthetic oil. Today when purchasing the oil at the dealership parts department, she mentioned that MINI is switching to 0W-30, but I have the option to stay with 5W-30. I decided to go with the 0W for better protection at startup since winter is coming and thinner oil is generally better anyway. The oil weight isn't the issue, it's the new ACEA specification.

But here's the problem. The 5W is ACEA A3/B4 while the 0W is A5/B5. From what I understand, A3/B3 offers higher performance under heavier loads (less shearing) than the A5/B5 which is geared more towards fuel economy/lower CO2 emissions.

Thoughts on which is better for the R56?

 

Considering the fact that you have a slight tune and probably drive the car harder than average, I'd go with the more high-performance A3/B3 specification. I don't think the A5/B5 would cause major issues but better safe than sorry.

Mobil 1's Euro Formula is 0W-40 and had been BMW LL01 certified for a while, then recently they changed the formula/BMW changed specification and so it no longer holds LL01 certification. I personally would continue using it because I know it worked well in my 08 MCS and I change my oil around 5k miles anyways, not the 10-15k recommended by the car computer. Plus, you can pick it up at walmart for $25/5qt

 

Here's a handy application guide and some background info:

http://new.minimania.com/Mini_Cooper...lacement_guide

Drive Hard. Drive Safe. Keep Grinning.