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      06-25-2014, 10:27 PM   #30

Drives: 91 E30, 11 135i cv
Join Date: Mar 2009
Location: New Jersey

iTrader: (0)

Originally Posted by Dackelone View Post
The engine oil can be either: 0w40, 5w30, or 0w30 with BMW LL-1 for the USA and LL-4 for the Europe. The main thing to check for is the LL-1 (BMW Long Life rating) or LL4 rating. Also... you can use LL-4 rated oil in a market that requires LL-1 but not the other way around! So the guys in the USA can use a LL-4 rated oil, but the euro guys should only use LL4 rated oil.

This is one reason I buy the expensive German Castrol RS Edge 0w40 (LL-4) oil for my 135i.

Given that LL-4/low SAPS oils are hitting the market in the USA, Id advise to beware of this.

Low SAPS oils, such as LL-4, MB 229.51 and VW 504/507 are suitable for use in diesel engines in the USA because of the low sulfur content of the fuel. However, in the USA, gasoline has a higher sulfur content.

The low SAPS oils have lower starting TBN and poorer TBN retention due to additive chemistry. Not an issue with ULSD, but it is an issue in gas engines running higher sulfur fuels without lean stratified charge DI, which is used (at least in some cases) in Europe where the NOx emissions regulations are not as stringent.

The outcome as a result is that the acid buffering capability used in gas engines in the USA gets used up far faster than the notional design approach intended. This can allow much more substantial corrosion and related issues, unless monitored closely by UOA for TBN and sulfation.

LL-4 vs LL-1 isn't about being more expensive, and if you look at the specifics of the BMW spec, there isn't much difference other than that LL-1 is based upon ACEA A3/B4 while LL-4 is based upon ACEA C3.

I would not run low SAPS oils in North American gas engines. I have run the UOAs and studied the chemistry performance myself. Wear performance of the additives in the low SAPS oils is just fine, so long as TBN is retained. But without active monitoring, its a crapshoot.