Several major oil companies, like Mobil and Castrol have extended interval change oils that are good for 20,000 miles or one year. Here is an interesting video where it is explained how they can back up their claims. Do you trust them? Can Engine Oil Last 20,000 Miles? Here's How Engineers Test That Claim (roadandtrack.com)
As a chemist that formulated engine oils for 18 years for Chevron, I learned that the absolute best thing you can do for an engine is change the oil. It is false economy to extend oil change intervals. The reason for changing the oil is not that the oil degraded, it is the fact that fuel combustion byproducts, unburned fuel and acidic components from combustion accumulate in the oil leading to deposits. Changing the oil is the only way to remove those combustion byproducts. Another reason to not extent oil drain intervals is that if you forget at 20,000 miles, you will really cause damage and deposit buildup in the engine. And doing it less frequently is an easy way to forget doing it at all. Just my view of things, but I have NYC Taxi Cab engine oil test data to back up this claim.
Yes, every claim or intelligent oil monitor, is less intelligent than the owner. Probably some green agenda crap where the oil companies are trying to appease someone.
