BMW (and other manufacturers) evidently do have Castrol add a "bit extra" to their OEM oils. For instance, my 335d uses a BMW LL-04 oil that is based on Castrol SLX. However, it's interesting to compare oils: VW specs Castrol SLX LL03, which is rated ACEA A3/B3 C3. BMW's LL04 SLX for the 335d also has the same ACEA rating (severe service low-HTHS, extended drain, low ash). It's come to the point that the SAE ratings are useless for modern BMWs.
Personally, I agree 100%. I pay the dealer about a $1.00 per quart premium to use the manufacturer's oil .vs. something I could buy at Walmart or Autozone, and in a $50K+ car, it just seems like cheap insurance to me. I guess if I put on 30K miles a year and changed it 6 times a year I might feel differently about using BMW oil.
are you assuming that what you get at the dealer is better than what you get at autozone? just because something comes with a bmw label does not necessarily make it better. many people think gc is superior to bmw label, and some people have had success with it reducing oil consumption. this has nothing to do with cost
No, the only assumption that I made is that the manufacturer employs a lubricant that it finds acceptable for the vehicle it engineered. Even then, I couple that with common sense, and I change my oil/filter every year/5K miles. Again, in the grand scheme of things, its simply cheap insurance, and the $1.00/quart more just isn't that much.. And, I agree with your "cost" comment... For me, it has nothing at all to do with costs, but everything to do with not second-guessing those with far more engineering experience than I have. Understanding the entire range of lubricant qualities (as well as their limitations) is far beyond most BMW owners "pay grade". What many people "think" is irrelevant to me.... Unless, those same people are willing to step up and pay for my repairs if their "thinking" turns out to be incorrect.
An Update ... To follow-up on my previous post: I have recently had my 15K service. I told them about the apparent high oil consumption (at that time, ~4 quarts in 6K miles, 5 months (almost five quarts, electronic meter in the iDrive was two increments from "Min")). I also brought up that the indications seemed to jump around, being low one day, normal or near normal another, then back down ... sometimes several notches either way in a day; I suggested that it was perhaps the sensor, not an oil issue. Their response was to measure the drained oil (8.5 quarts out), add the new oil (filters, etc.) and seal the filler (I guess so that I won't screw with the quantity), and install a new sensor. It's been a couple thousand miles since, and the oil level is still nailed to the "max" line in iDrive, so I believe the sensor was the root issue and I spent the first couple months of ownership burning off excess oil . The car is running great, I'm getting used to it not being an SUV (I drove large SUVs for ~25 years before the BMW), and having some fun on the road. Thanks to everyone posting on the forum, problems and solutions; it's been helpful for me understand issues/non-issues and "how things are" in the world of BMW ownership.
to be clear.. german castrol is bmw approved. bmw finds many lubricants acceptable for their vehicles. and i'm guessing the op does care what other people "think".. which is why he posted posted the question here.
