Originally Posted by 370Z Purist

I change the oil twice a year; I've done the first oil change at a local lube station using their "full synthetic" service for 50 dollars; valvetrain noise was insane. Despite my specific instructions to leave the car alone, my father took it upon himself to change the oil. He's also driven it enough, badly enough so that my clutch noticeably softened, but that's a story for another time.
The next time was at a Nissan dealer at 5000 miles (cost me 89 dollars with a coupon! insane! this is for their special "ester oil" too) was the next one. After that, I did Redline at 7000 about 8 months later, then I did Royal Purple this winter at 10000 miles. I've had about 6-8 months between changes, average.

I have noticed that after the oil change at the lube joint that the valvetrain noise was very very loud and clicky; enough to actually hear from inside the car. Nissan's Ester Oil and Redline both significantly reduced this noise, and Royal Purple is a bit louder. I've decided to go with Redline for the rest of the foreseeable future.

Also, funny story; my friend is very mechanically inclined but his parents are not; their 09 outback sport went 40,000 miles without the VERY first oil change. Since then he has taken it upon himself to change it every season, and it still runs very well. It would appear to me that as lone as there is some oil in the car, it doesn't really seem to matter as long as it isn't driven like a track car. More or less, though, with our cars, it's probably a better option to do at least a yearly oil change, ideally every six months.

Of course, that's just my two cents, and my personal experience. The oil debate will go as long as there is anything that ever needs oil. Might as well go with what you know or what you believe.