WSAYERS you sound like quite the conspiracy theorist lol. Not that I think you are, you just sound like one. haha. I agree that 3,000 is early, but it's also a general rule of thumb. It's easier to talk about than to tell people, well on regular oil and in a newer car you could go 8-10,000 miles if you do mostly highway driving with minimal dust, but if you live in the country and tow a lot or if you live on a really dusty dirt road, or if you have a lot of short start stop trips you maybe should do earlier blah blah blah right so they took a shot at a number. Is the number going to be on the short side in the name of some more sales, yes I'm sure, but at the same time is it a fairly reasonable estimation to cover all types of driving under one rule, yea it's fairly close.
My dad wouldn't change the oil in his truck but once a year MAYBE which meant he was driving 20k+ miles per year on his oil. Did his truck run? Yes. In fact it ran well for many many years, but when it did start failing it didn't take long and the whole engine failed. He started having problems with the engine burning a lot of oil...probably from over-worn seals because it was getting sludgy. It was also a 1991 engine where tolerances weren't as tight as they are today.
Personally I just like to change my own oil from time to time and take a good look at the oil that comes back out of the engine. If it's nasty black and thick I know I should probably not run on it as long as I did. If it's still in pretty good shape I know I can go longer on it, but I definitely prefer it always looking a bit on the clean side because that means the engine is staying clean. It's also good to always check the drain plug on the oil. For those that don't know, they are magnetized so that any metal shavings from inside the engine end up stuck to this plug and not recirculating and gouging things. Normal wear would be a thin layer of practically indiscernible metal shavings. It basically should just appear to be gooey charcoal. If you find large chunks of metal (clearly visible size pieces) you might should worry a bit.
