I still remember learning from my father how to carefully remove a dipstick to check the oil level in our cars. It was drilled into me that oil needs to be changed every 3,000 miles or so.
Childhood habits are hard to undo, but sometimes we need to throw aside our parents' good advice.
"There was a time when 3,000 miles was a good guideline," says 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, Reed says. A better average, he said, would be 7,500 between oil changes, and sometimes up to 10,000 miles or more.
The California Integrated Waste Management Board ran public service announcements for several years about "the 3,000-mile myth," urging drivers to wait longer between oil changes. The concern is not only the cost to drivers, but also the environmental impact of throwing away good oil, says Mark Oldfield, a recycling specialist for the agency.
Robert Sutherland, a Pennzoil scientist who works at Shell Global Solutions, says that rather than picking a number, you should follow what your owner's manual advises.
Checking the manual for my 2007 Mazda5, I first had to determine whether I did a lot of "severe driving" -- things like stop-and-go driving, going short distances, extended idling, taking muddy, rough or dusty roads and driving in really humid or cold temperatures.
Since I do a lot of short-distance and stop-and-go driving, I was advised to get the oil changed every 5,000 miles. If I tended toward longer-distance highway driving, it would be every 7,500.
Unsure when to change?
- Blackstone Laboratories in Fort Wayne, Ind., specializes in analyzing oil. Send in an oil sample, and for $25, they'll check for engine wear, oil viscosity and more.
- The lab runs about 150 samples a day, and a fair percentage of those are consumers looking to find out how often they need to change their oil, says Kristen Huff, a vice president at the company.
- "Very often, it is the case that they're changing their oil too often," she says. "They do what their dad did with his '55 Chevy."
Another way to assess your oil needs is to buy a car that has a maintenance minder, such as a Honda. A light on the dashboard alerts the driver when the system judges that the oil has only 15 percent of its useful life remaining. The time between oil changes varies depending on the driver and driving conditions.
Honda has used maintenance minders on most models for at least the last five years, says Chris Martin, a Honda spokesman. Previously, the owner's manual suggested changes every 10,000 miles in mild conditions and 5,000 miles in severe conditions.
Still, some people stick to the 3,000-mile changes, because "the Jiffy Lubes of the world have done a good job convincing people," Martin says.
It's not just the fast oil-change outlets. My sticker from my trusted mechanic states that I'll need a change in 3,000 miles or three months.
Reed of Edmunds.com says car owners often get conflicting messages because of an inherent tension: "The car manufacturers want the reputation that it makes cars that last a long time. The dealership wants to see you every three months."
But he acknowledges that "3,000 miles strikes a deep chord with the consumer," adding: "It feels good to get an oil change. If you fill up the car with gas, wash it and change the oil, it runs better. Of course, it doesn't. But it's the perception."
Although Reed is doubtful that most drivers fall into the severe-driving category and fears mechanics will use that to push drivers into paying for more oil changes than necessary, Sutherland says he wouldn't want "to second-guess the manufacturer." Vehicles, he says, "are a substantial investment, and changing fluids is how you protect that investment."