I own a lot of heavy equipment that is ran under the most demanding of conditions. Nearly all of our newest engines are requiring
oil changes at 500 hours with a new filter every 250.
I own a 2005 Ford super duty with a hour meter on it after 658 hours it registers 28,556 miles on the odometer. I have changed the
oil 3 times. Our company uses a
oil testing service and the second oil change was unnecessary and recommended extending the schedule to 12-14K miles. If any of you are at all concerned I would strongly recommend having your oil sampled and tested not only will it may vastly extend your oil change interval but will alert you to possible internal problems.
I hate to say it but I have to agree with CA here, the marketing of oil changes at every 3K is an abuse of a resource.
Scott S