I saw this article today and my opinion is that the general public is being given bad advice.
“There was a time when the 3,000 miles was a good guideline,” said Philip Reed, senior consumer advice editor for the car site Edmunds.com. “But it’s no longer true for any car bought in the last seven or eight years.” Oil chemistry and engine technology have improved to the point that most cars can go several thousand more miles before changing the oil, Mr. Reed said. A better average, he said, would be 7,500 between oil changes, and sometimes up to 10,000 miles or more.
I personally change my oil at 3,000 miles and if someone wants to push it I wouldn't advise going beyond 4,000. I have saw far too many vehicles with engine trouble and failure due to sludging. Today we are servicing a 2009 Ford F-150. The leasing company is using a 5,000 mile interval on its oil changes but is not taking into acccount the fact that this vehicle is never shutoff due to the equipment on board until the end of the day once it is started up. The hours it runs far exceeds the mileage driven. We recently had to install lifters in a 2006 Dodge Ram pickup with a Hemi due to pushing the service intervals. This customer is now a confirmed 3,000 mile oil change interval adherent aftering spending $1,700.
Besides sludging issues we have saw on many vehicles I am firmly convinced that having someone change the oil and look at a vehicle every 3,000 miles or 3 months is a service the consumer needs. Often we catch other problems and can fix them before they become big ticket repairs.