Quote:
Originally Posted by j1980mac
Lol don't go off of my recommendation. I'm not a mechanical engineer. I don't know anything about oils other than I don't wish to stray too far away from OEM.
When I was referencing LL04, what I really meant was LL01 (my oversight).
LL01 and LL14+ are BMW approved oils for the B58 according to my X3 M40i manual.
I don't know that LL04 would be a good thing (or not) for our engines.
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So, something that I'm not sure is obvious... One of the big things about these OEM-approved oil specs is the additive list. When the german OEMs started moving to direct injection, they had to do something to address carbon buildup on the valves. Contrary to popular belief, they knew about this issue, and DID do something to mitigate it. The SAE (I think it was the SAE, it may have been a different automotive organization though) had done studies on how to mitigate the carbon buildup and found that oil additives could make a noticeable difference without requiring drastic engineering changes.
So, BMW, VW/Audi/etc, created specs that require certain additives in the oil to fight carbon buildup. They don't prevent it, but they reduce it.
So, I would suspect, the LL-01 was the first oil with those additives for gasoline engines, and LL-14 is the updated spec with lower overall friction for higher efficiency, and possibly new/different additives for the same purpose.
The rest of this is just my experience, but it is informing my current choices:
My last car was also direct injection, modified, and I didn't run a catch can. At about 60k miles, I was getting the intake manifold replaced under warranty and the dealer offered to walnut-blast the valves for cheap since everything was off.
I had them take before/after pictures, and showed them to my tuner. My valves were WAY cleaner for a 60k tuned car without a catch can than most 30k tuned cars with catch cans.. most of whom run 'high performance' oils without the OEM approvals, while I ran fully OEM-approved oil with half-duration change intervals. I think the combination of using the OEM-approved oil, and reducing the change interval to ensure the additives didn't get used up, kept my valves way cleaner than if I had been using a 'high performance' oil without the OEM-specified additives.
So, I won't run an oil that doesn't have the BMW spec on it (Well, I MAY be convinced to run an oil with an equivalent VW/Audi or Merc spec, but I'd have to do some research on BITOG or similar to see what may fit the bill..) but since I also don't feel the need to run a super-heavy oil, the OEM oils seem sufficient to me. I just don't let the car go the full duration between changes. (It is worth noting that the condition-based servicing alone lowers my change intervals from the quoted 10k, but I'm probably hovering around 5k-6k changes, on average, because I'm always at the dealership a couple k early and just get it done while it's there.)