Originally Posted By: brentalan
M1RACING FAQ:
http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_Racing_Oil_FAQs.aspx
"You say that Mobil 1 Racing oils are not for street use. Why is that? Does that mean I can't use these oils if my race car is also my daily driver?
Automotive street use oils that meet the latest industry standards are required to have a lower level of Zinc and Phosphorus anti-wear chemistries than oils formulated years ago. The latest automotive street use engine oils are designed to be compatible with emission control equipment. Mobil 1 Racing oils are formulated with anti-wear (Zinc/Phosphorus) chemistries at twice the level of automotive street oils to provide enhanced protection of highly loaded valve train systems found in some race engines. Based on the high level of anti-wear chemistries, Mobil 1 Racing oils are not recommended for street use."
So.....2 questions are answered here:
1) It is not recommended due to cat converters on the street
2) You probably don't need it in the BMW b/c it's not a highly-loaded flat-tappet design.
Also, even though they do not mention it, I once heard that since this is considered a TRUE race oil, it has a MUCH reduced (if not absent altogether) detergent pack.
What IS suprising though is that IF the above is true, it still has a VERY high TBN for a race oil (I'm guessing to handle extreme fuel dilution??).