Do you still have that feeling that you
need to change your oil every 3,000 miles?
Well it's just a feeling, not fact.

Here are some quotes:

“Although oil companies and quick-lube shops like to promote this idea [that engine oil should be changed every 3,000 miles], it's usually not necessary. Go by the recommended oil-change schedule in your vehicle's owner's manual. Most vehicles driven under normal conditions can go 7,500 miles or more between oil changes. Some models now come with a monitoring system that alerts the driver when the oil needs changing. Depending on driving conditions, these can extend change intervals to 10,000 or 15,000 miles.”
– Consumer Reports, December 2006

“Most major automakers agree: The adage that you should change your car’s oil every 3,000 miles is outdated, and even 5,000 miles may be too often.”
–Tom Krisher, Associated Press, in the Desert News, March 26, 2007

“…for the vast majority, 5,000-mile oil changes will help your engine last to a ripe, old age.”
–Tom and Ray Magliozzi, hosts of NPR’s Car Talk, on MSNBC, April 17, 2006

“Most manufacturers now recommend changing the oil every 7,500 miles. We recommend doing it every 5,000 miles, because we tend to be more cautious about protecting the engine. Very few people recommend changing the oil every 3,000 miles anymore. It's just not necessary, and the environmental cost is too high.”
–Tom and Ray Magliozzi, hosts of NPR’s Car Talk, in the Detroit News, April 6, 2005

“Conventional wisdom has held that the oil should be changed about every 3,000 miles. This notion has been ingrained into people's heads for decades, in part as a marketing ploy by oil companies. The 3,000-mile interval made sense when engines used single-grade non detergent oils. But with the latest oils and car designs, it's no longer necessary to change oil that often under normal driving conditions.”
–Steve Ritter, in Chemical & Engineering News, March 13, 2006

“Synthetic oils, because of their better properties, need to be changed less often, at intervals up to 25,000 miles or more. In the end, the best advice on the type of oil to use and the frequency of oil changes is to follow the manufacturer's recommendation in your car owner's manual.”
–Steve Ritter, in Chemical & Engineering News, March 13, 2006

“I remember getting my first car (a hand-me-down) and how my father kept telling me how important it was to change the oil every 3,000 miles. A lot has changed since then. Today’s oil is much better, and it can last a lot longer. Here’s what to do: Check your owner’s manual and follow the manufacturer’s recommendation.”
–Herb Weisbaum, MSNBC Consumer Man, April 17, 2006

I will add that most quick lubes offer a
basic petroleum oil and a low quality filter and
that combination isn't good for too long.
By using better oil and better filters you
can go farther between changes.