Originally Posted by Pretherius
Well... sure. I had an '02 Taurus with bearing trouble. I bought it with 35K on the clock. Maybe it never had an oil change. I just find that unlikely.
I guess we'll have to agree to disagree, then. Oil--like coolant, transmission fluid, power steering fluid, brake fluid--doesn't stop working all of a sudden like flipping a switch. It's a long, slow progression from "perfect" to "might as well run mud in the crankcase." If your carmaker suggests changing the oil at 10K but I insist on changing mine at 7,500, you're putting 1/4 of your miles on with more worn down oil than I am. Maybe your engine lives long enough to see you sell the car regardless, and maybe it doesn't. But your odds are certainly better changing fluids more often. (Whether that's worth your extra time and money is a separate philosophical discussion.)
Peace of mind isn't worthless either.
Or maybe that engine had defective bearings, or a bad design. In either case changing the oil every 100 miles would have made NO difference.
You are right, it is a long slow progression, and as I noted many, many, many tests have been done by oil companies, car manufacturers, independent labs, etc. over the years that have proven that the threshold where oil starts to become ineffective is way beyond what the suggested maintenance intervals call for in all cars.
I was an expat living and working in Europe for quite a number of years, and they have been recommending extended changes intervals (typically 1.5 to 2 times longer than ours) for 20+ years. The oil life monitor in the BMW I had usually came on for a change around 16,000 miles on average, and that's with regular autobahn blasts (foot to the floor). There has been 0% increase in engine failures as a result.
Again, do as you please, but you are not benefiting your car, only the oil companies (who indeed will appreciate you for it).