Gentlemen,
You just can't type the letters BMW (particularly on this forum) without getting into a discussion with the factory suggested approximate 15,000 mile OCI with their dealer supplied oil. Without it, we BMW drivers would be reduced to only discussing the cooling system and the control arms / bushings.
My car had 3 runs on this regimen when I got it. Either out of paranoia, curiosity about the Auto Rx phenomenon, or what have you, I took the Auto Rx plunge. On Thursday evening I completed the 3,000 mile rinse phase. So I changed the oil and filter. It has Mobil 1 0w-40 in there now. I'm planning on leaving it in there until the service indicator tells me to change the oil again, which currently is about 10,100 miles. We'll see what comes of that, I'm probably going to send it to get analyzed then.
So what are the results of Auto-Rx? Well, the oil itself looked pretty good after a 3,000 mile rinse of Chevron dino. For any BITOGers out there who get irritated about an oil turning black soon, I'll suggest this Chevron dino oil. It stayed its original clear color for practically the whole 3,000 miles. Now this doesn't prove anything, but I still thought it was kind of interesting. No obvious impurities, sludge, or foreign matter came out in the drained oil.
I changed out the oil filter, of course. It is cannister type filter, for anybody reading this, who is unaware of how BMW oil filters work. Inside the oil filter housing, it all looked great. The filter looks...perfectly normal. Nothing but oil in there. I've looked closely at the pleats, and I can't find any specks of foreign matter or any evidence of sludge.
Just looking at the drained oil and filter there is no obvious sludge problems with this car after going through BMW's suggested oil change procedures for 3 years and 46,000 miles or so. Perhaps the Auto-Rx treatment liquified whatever gunk there might have been in there.
Now I didn't have any oil analysis done, so I can't comment about that. But from what my results indicate, following BMW's suggested routine with their oil does NOT result in a sludged motor--at least through 45,000 miles. I'm aware that there are posts out there for people followed this and have major sludge problems. I have no explanation for this difference. Local BMW mechanics have informed me that they have only seen problems on cars that just don't get driven much out on the highway, don't get up to operating temperature much, etc. You know, really severe service.
I'll probably do intermediate oil changes after I finish the expected 10K MObil 1 0w-40 run, instead of the whole 15,000 mile distance (just because I am a BITOGer and get a perverse kick out of studying oil).
The car drives great. For all the accusations out there that BMW is trying to destroy your car with this service routine, I am not convinced by the evidence I have seen on my car. Maybe the benefits of shortening the OCI only shows up when it gets older, to 100,000 miles and beyond? Possible.
Incidentally, there is alot of bandwidth taken up around here complaining of noises or racket from using Mobil 1. I can only report that after a few days of using it, I'm not hearing any strange sounds, or just a louder engine. But then again, I'm the sort of guy who often drives without a radio on because I LIKE listening to the sound of the symphony coming from a great running inline 6 internal combustion engine.