I own a vehicle which I put less than 1000 miles per year on. It currently has about 5500 miles on it. I did an oil change at 3500 and put synthetic in it. My question is about the stability of conv. vs syn. in this situation. Many oil mfg. have started saying you should think "months not just miles" in their advertising. I have heard anecdotal reports that conv. oil will loose its anti corrosion properties over time. I don't recall anyone stating that syn. does the same, but it may very well do so as well. So the issue is should I use conv. oil and change it every year or use syn. and leave it for a few years? Third option would be conv. and leave it in until I put another 3500 miles on it which should still be well within the lifespan conv. unless the anti corrosion properties factors into it. What say ye all.