Our 2004 X3 2.5 calls for BMW synthetic oil 5W30 or 5W40 with API SH or higher. Will using another synthetic oil 5W30 with API SM void the CPO engine warranty?
If you use the correct type of oil for the climate, with the correct oil level, changed at a regular interval, your engine will never be damaged as a result of what oil you use. You don't have to use BMW's oil.
However, you do have to meet the minimum API service level to protect your warranty coverage. The service specifications are assigned in alphabetic order and are backwards compatible: SM exceeds SH so you are fine. The brand does not matter if it meets the API and viscosity requirements.
The BMW 5w-30 is different than most other US spec 5w-30 oils, it has a higher HTHS viscosity >3.5. BMW specs a oil rated as BMW-LL01, very few oils at most auto parts stores meet this spec. Mobil 1 5w-30, 10w-30 do not meet the BMW-LL01 spec, Mobil 1 0w-40 does. Castrol Syntec 5w-30 does not meet the BMW-LL01 spec, but the 0w-30 does. The oils listed below meet BMW's Long-life rating and are acceptable for use in BMW Passenger vehicles and SAVs in the US market with gasoline engines. http://www.bmwusa.com/Standard/Content/Owner/SyntheticEngineOils.aspx
The Long Life rating only means that it can go an extended interval, right? If that's the case, you don't need a Long Life rated oil because you shouldn't be dragging an oil change that long in the first place.
I change my oil every 2500-3000 miles. It's the cheapest form of insurance you can have for your engine. Mobil One is used here. I am thinking about switching to Red Line and extending my intervals to 5000 miles.
The newer BMW oil spec does not just mean Long Life oil. This is a misconception that many folks have. The chemistry is different also and this is paramount. As an example LL-01 is the required oil spec for 2006 and newer BMW gas engines operating within the U.S. The rest of the world (ROW) requires LL-04 oils for the same engines. Both are Long Life oils but the chemistry is different and the LL-01 oils work better with higher sulfur gas sold in the U.S. That's why LL-01 is required to maintain your new vehicle warranty. LL-04 oils do not meet U.S. gas engine new vehicle warranties and are not to be used according to BMW NA. It's always best to use the proper spec and viscosity oil for your engine to prevent premature wear. In extreme cases you can actually experience engine failures by using the incorrect spec oil. http://www.bmwusa.com/Standard/Content/Owner/SyntheticEngineOils.aspx As far as determining the proper oil change interval, that is best achieved with a Used Oil Analysis, (UOA) that eliminates guesswork. There is no advantage to throwing perfectly good oil away. http://www.bobistheoilguy.com/cms/i...catid=40:past-articles-of-the-month&Itemid=78 Also note that many purveyors of boutique oils intentionally use deceptive advertising to imply that their products can be used where a specific BMW approved oil is required. They will say things like: "Recommended for BMW spec ABC", or "Meet's all Euro car requirements", etc. Unless an oil has been tested by BMW to meet their engine oil specs, a company can not claim that it meets these specs and typically these boutique oils do not meet the BMW oil specs.