Why not more than 1 year?

[PT1]

I regularly go 1 year with my motorcycle & boat but never with the auto's. Just too easy to change at 5000 miles and all the engines still purr at 150k on the clock. So, I am convinced that regular OCI's are an inexpensive way to keep your auto investment dollars working in your favor. By using this OCI interval I have never had an engine that would consume more than 1/3 QT in 5000 miles even after 100k. My wife has a Toyota that is over 125k and I am taking it over 200 and maybe to 300k just to see if it will do it. When you look at your average cost pe mile on any vehicle that goes over 150k it just makes good sense to run a conservative maintenance schedule IMO. OK, now start the flamer.

 

[heathenbrewing]

The oil will thicken over time and form waxes in cold weather. The thickening is permanent.

 

[Dr. T]

I also agree that with synthetic (can't speak for dino), mileage is somewhat more important than actual time. For example, I do 10k mi. OCI's. Well that takes me more than 2 years on a car that I recently began storing. I won't be doing annual oil changes that cost $100 (8qt.+ $25 OE filter)on oil that is still good after a measily 3k and 12 months.