My truck burns oil so I have only officially changed the oil in it once. I just added 4 quarts 3 days ago so it's like an oil change
4 quarts! That things got serious issues!
What do you think if someone went 9,000 miles WITHOUT changing their oil?
Back in the times when engines weren't expected to pass 100k or so, 3k/3mo was pretty much necessary for changes. This was also due to the fact that oils weren't nearly as good as they are today.
In these times, even dino oils have great detergent packages, so 5k/6mo is fine. With a full synthetic, 10k+ is easily attainable. Heck, if you read the bobistheoilguy.com boards, you'll see guys running the very oil we're supposed to use (Motorcraft 5w20 synthetic blend,) to 15k, and they still get good results back from their used oil analysis's.
well, oil never goes bad....
but the additives do wear out, and sludge does build up....
so nothing is really BAD.... its not ideal, and as long as the oil isn't low you will be fine.
Hell, my work van has over 200K miles on it and We just ADD oil now and then. Still runs like a champ, even though its a dodge.