California thinks you probably change your oil too often:
“Our survey data found that nearly half of California drivers are still changing their oil at 3,000 miles or even sooner,” said Mark Oldfield, a spokesman for the California Department of Resources, Recycling and Recovery, which has launched the Check Your Number campaign to encourage drivers to go with the manufacturer’s recommendations.
Improvement in oils, friction proofing and car engines have lengthened the oil-change interval, typically 7,500 miles to 10,000 miles for most vehicles.
Changing motor oil according to manufacturer specifications would reduce motor-oil demand in California by about 10 million gallons a year, the agency said.
I did actually “check my number” on their site, and it did cough up the correct figure: 3750 miles. I am concerned, however, that it doesn’t cover any vehicles before model year 2000, some of which may actually require 3000-mile oil changes. (And curiously, they had no number for my previous car, a 2000 Mazda 626, which specified a 5000-mile interval.)
It occurs to me that at least some of the 3000-mile folks may be offset by the people who don’t change their oil until it’s baked into a giant puddle of sludge. And I think we can assume that manufacturers who offer free scheduled maintenance during the warranty period — Volkswagen or BMW, for instance — will embrace this idea enthusiastically. I quote a tech on Bimmerforums:
As far as I’m concerned, BMW gives you free oil changes every 15k, and anyone who doesn’t insist on additional changes is a fool, or intends to kill their car at an early age.
In the five years I’ve had my current car, the average mileage between oil changes has been about 4200. Nissan’s non-severe schedule will let me slide to 7500, though I’d rather not push my luck that far.