I'm going to step out on a limb here & voice my $.02 about oil. I'm an old fart my most of the forums standard & have been a 'car nut' all my life. Using ONLY the BMW approved oils is ridiculous.
1. First, BMW is NOT going to test every oil on the market. They WILL look at the 'major' brands, and especially Castroil since they made a deal with them to supply their factory fills. You can bet that they were the cheapest quoted contract. I have dome business with the BMW plant in Spartanburg or their 1st & 2nd tier suppliers ans PRICE is the bottom line.
2. BMW's LL-01 oil spec is based on European standards, NOT USA standards. That's why they replaced so many nikasil 4.0l V-8's. OUR hight sulfur content gas made from high sulfur oils caused the engines to corrode due to the un-burnt sulfur in the cylinders. That was NOT a problem in Europe OR California. The European standard is "ACEA"
& BMW's spec is A3/B3, A3/B4
, and then they add API (American petroleum Institute) Use only oils with an API rating of SM or higher
Then on there web page http://www.bmwusa.com/Standard/Conte...ngineOils.aspx
they spell out the "approved " USA oils.
The reason for the move toward the "0W" & "5W" is for fuel economy. This has been the big push by the the government for years. The low end number makes it easier to meet these requirements. Not to say that thin oil on a cold day isn't good; it is. But to argue over a 5 w & a 10W is crazy. IT will not destroy your engine.
Go to Walmart & look at the specs on the back of the Mobil 1 "European" 0W40 oil. It says meets ACEA A3/B3, A3/B4 & is API SL,SM, SN. SN is the latest "improved" designation by API. Now look on the back of all the other grades. Just about all of them meet the API SL,SM,SN. Not all meet the ACEA A3/B3, A3/B4. HOWEVER, look at the Mobil 10W40 high mileage jug....it meets the same specs as the 0W40, both USA & European. It will work fine year round unless you live in Fargo.
3. The BMW web page also states: The choice of the right SAE grade is based on the climatic conditions in the region in which you normally drive your BMW. So use some common sense here. Most newer BMW's have it molded in the plastic "USE Castroil". Did you ever wonder why?
Conclusion: Use a good named brand of synthetic oil (it cleans better) for newer cars; and use an oil weight dependent of where you live. Check the Bentley BMW service manual: It calls out 5W30 in a temperature range from -20F to about 60F & 15W50 from 20F up to above 80F.
Use you heads guys. Change oil & filter with a good grade Synthetic oil about every 6000 miles. Even BMW's computer will tell you 11-12k miles, which IMO, is TOO long. BUT every new car dealer will only do it when the computer says so.
sorry for the rant......