Oil change schedule: mileage or time?

I’m sure there’s been a discussion on this, but search isn’t being very kind to me.

I’ve usually stuck to my owner’s manual with regards to auto maintenance, and it has oil changes scheduled every 5000 miles. Well, I’ve recently reduced my regular driving (new house closer to my work, and I’ve also been telecommuting more often), so when I happened to glance at my “next change sticker” this morning, I noticed that my last one was back at the beginning of January. I’ve only put ~3500 miles on the car since then, but I was wondering whether there is any reason to get a change based solely on time. Can the oil break down just sitting in the oil pan?

So, is there any reason for me to go get an oil change now (since it’s been almost six months), or just wait until the odomoter rolls over to 65k around late July?

I use a combination of time and mileage. Today’s oils are pretty good at avoiding breakdown, etc, but it’s still 20 bucks to maintain a peace of mind.

The old rule I used to use was every season, change the oil, or about 4 times per year. With newer synthetic oils you can supposedly go 12,000 miles or more between changes.

If you’re constantly making lots of short trips, say 15-20 minutes or less and the engine has time to cool down between trips, these are severe driving conditions and you should probably be changing oil more often, maybe every 3 months, or 3000 miles. Your manual might say something about severe conditions. I think the primary problem, w/ this kind of driving, is condensation of water vapor contaminating the oil and forming destructive acids.

Both sound reasonable. And A.R. Cane, that’s pretty close to my driving habits now. I live ~15 miles from work, about half of the trip is highway, and it usually takes ~20 minutes. I use a synthetic blend oil, so that might save me a bit, but I’ll double-check my manual to see if there’s any recommendation regarding severe driving. Honestly, I would’ve figured that would be in the other direction: lots of long, constant drives. But now that I think about it, I do remember hearing that most of the wear on an engine is during the “warm up” period, so many short trips (having a higher percentage of mileage during that time) being more severe makes sense.

Thanks for the responses.