I had two jobs where we tested lubricants and their role in keeping mechanical devices running. Maybe what I learned will be helpful.
The first job was at big Vickers/Sperry Rand gear products division in Tulsa. We ran transmissions and gear boxes on a dyno to destruction. Temperature of the lubricant was the critical factor. A transmission under heavy, measured, load was run while temperature was maintained. The temp was raised higher and higher as the gearbox ran. Periodically, we would check wear on the gears and bearings. Day after day, the transmissions ran until we raised the temp another 10 degrees and the gears cratered. The gearbox would run perfectly until we hit that breakdown point of the oil then the box was destroyed! As little as 10 degrees made the difference in running well or complete destruction! Temperature of the lube was absolutely critical!
In the second job, I worked for McDonnell Douglas aircraft and maintained ground support equipment for military and commercial jet aircraft. Ground support equipment (GSE) has hydraulic systems built into the unit so the aircraft systems can be function tested while the bird is on the ground. Aircraft folks are FANATICS about about keeping GSE clean as hooking a dirty unit into a clean aircraft system trashes the aircraft system.
We took samples of the oil for lab analysis of viscosity, particle count and acid number. The particle count analysis was so strict that if you TOUCHED the open sample bottle neck with your finger, the sample would fail. If a sample failed, we re-sampled. If it failed again, the huge banks of filters were changed, system circulated then re-sampled. The filter banks had up to 35 6"x18" cartridge filters in each bank with up to 3 banks in each unit.
If the sample failed again, all oil was dumped, another filter change, flushing and a period of running to recirculate. Cleaning one of those GSE units was a HUGE expense but compared to trashing a $30 million aircraft, it was a bargain. At the time, Mil-H-5606 red oil for the military jets cost $8/gallon and the Skydrol and Hijet synthetic oil cost $36/gallon. We dumped hundreds of gallons of oil! God only knows what the filter banks cost to restore.
Summed up, my experience taught me:
The biggest factor in having oil do its job in keeping a machine running is temperature. If temperature is kept to acceptable limits, how much crap you put INTO the oil determines how long the oil can be safely run.
With the car shown above, I'd say water was getting into the oil either from the combustion process or a coolant leak. Someone suggested sabotage. It has happened before. Either way, that car is toast.
Flash
That's interesting stuff, and I agree with you on what kills oil. Particulate can usually be filtered out (newer filters are very good), but temperature is crucial. I also agree a lot that conditions are what matter most in determining how long you can run the oil. If I was driving out to El Paso and back every day, then yeah I'd be fine changing my oil every 15,000 miles. But for your typical driver? No way.
A switch to a run hours interval would be great. I've thought several times about putting an hour meter on my own car for that reason alone. If you're running 70 miles an hour, you're going to do as many miles in about four hours as I do in a typical work week. So mileage is really one of the worst ways to determine if oil should be changed, but we can't get away from it for some stupid reason, even in the age of computerized-everything on cars.
This wasn't water contamination, though. That looks like a milkshake since being pumped through the engine emulsifies the water into the oil.
I run the oil in my BMW 12-15k (depending on what the on board computer tells me) and I have never see anything like this.
At work we have pictures of this happening in BMWs, too.
Let me put it this way - we don't make money off oil changes. Techs get paid a half hour to test drive a car, pull it in, do an inspection, change the oil (which is getting tougher and tougher to do with all this plastic on the bottom of cars), inflate tires etc. and test drive again. I know I don't make money changing oil, and I know the shop doesn't either. But we suggest 6,000 mile oil changes, and suggest that new BMW owners change the oil on their dime in between scheduled changes.
Much discussion on the Volvo boards re: Euro marques recommending 15K miles between changes of FULL SYNTHETIC oil. Volvo uses a syn-blend here in the States and recommends 7500 miles for oil change intervals. It's quite interesting when the dino-guys and the syn-guys go at it . Back in the old days, I was a 3000 mile oil change nut...even when I didn't have the money in my pocket. I've never had an oil-related engine failure--going as far back as my 1960 Stude Lark VIII. I stick with the factory recommendations of 7500 miles now...I'm not ready for 15K miles! Rancher B-I-L has over 350K miles on his F ?350? dually. I reckon diesels have different requirements, but 350K miles of dusty hot Texas workin' sounds pretty good to me!
Synthetic is the only way to go these days. But it will still sludge up if you run it too long. Engines are going up in specific power and down in emissions. They're becoming severely over-stressed with everything that's being asked of them, and something has to give somewhere.
The main reason I see for the uber-high mileage changeout with BMW and a lot of other Euro brands is their free maintenance programs. They're trying to cheap out. There is also environmentalist pressure to cut down on used oil. BMW caved to the greentards quite some time ago; word in the industry is that recycled plastics are the reason that their cooling systems break so much.
And yeah, diesels are different. Diesel trucks have huge oil capacities for one thing. For another, I don't think they're seeing nearly as high combustion temperatures as these gasoline engines.