3000mi changes are still recommended by a number of shops, but that has more to do with repeat business. There is nothing 'wrong' with the 3000mi interval, it's just not required in this day and age, mainly do to the reasons I've previously outlined.
In my daily driver, I change my oil 2 twice a year. That equates to about an oil change every 7500 miles. Back in the days of carbs, I subscribed to the 3000mi interval. The base oil lasts a looooooong time. It's the additive packages in the oils that take a beating, obviously the contaminants from combustion and water from condensation.
I maintain 2 engines in my 'toy' cars. One is a $50,000 supercharged 526ci HEMI that makes 1629hp at 8000rpm with 20 pounds of boost pressure in it's 'street' tune-up. The other is a $35,000 417ci naturally aspirated small block, that spins to 9000rpm and makes over 900hp. I cannot afford to make mistakes with things like oil and filters. I have been in the dyno cell when testing on engines costing over $100,000 and making upwards of 3000hp were taking place. I see what gets poured into the highend builds.
If anyone is really interested in this topic, there is a place to get excellent information. The site is called, Bobistheoilguy.com
Trust me.
