Stop Changing Your Oil

Photo: Matthew Ng | Getty Images

Oil chemistry and engine technology have evolved tremendously in recent years, but you wouldn't know it from American car owners' quick-change behavior. Driven by an outdated rule of thumb to change our engine oil every 3,000 to 5,000 miles (a rule that oil producers and service shops are happy to perpetuate), Americans spend millions on unnecessary oil changes that result in millions of gallons of contaminated waste oil. Even the most cautious owners are dumping their engine oil twice as often as their service manuals recommend.

Most new cars use synthetic oil. That means you typically only need to change it at the 7,500-mile mark or even wait until 10,000 miles. Some cars are even rated to go 15,000 miles between changes. These types of intervals assume mostly light-duty driving. If you drive your car hard, if you like to race on a track, if you're often stopping or starting (such as using your car as a ride-share or delivery vehicle), or if you drive on dusty roads, you'll need to schedule more frequent changes.

On the other hand, don't wait too long regardless of advances in oil technology. Don't change your oil every two years, for example, even if you rarely drive your car. Most manufacturers don't recommend leaving the same oil in your engine for more than a year.

After interviews with oil experts, mechanics and automakers, one thing is clear: The 3,000-mile oil change is a myth we need to lay to rest.

• How the 3,000-mile oil change myth persists
• Who benefits from more oil changes?
• Today's oil goes the distance
• The environmental effects
• When is the right time to change your oil?

How the 3,000-mile oil change myth persists

Part of the blame for this overservicing lies in our insecurities about increasingly complicated engines that are all but inaccessible to the average driver. Pop open the hood of a modern car, and a mass of plastic covers wall off the engine. On some vehicles, the only thing an owner can easily access is the oil cap.

"Vehicles are so sophisticated that oil is one of the last things that customers can have a direct influence over," said an engineer in GM's Fuels and Lubricants Group. "There's maybe some feeling that they're taking care of their vehicle if they change their oil more often."

The 3,000-mile myth is also promoted by the quick-lube industry's "convenient reminder" windshield sticker. It is a surprisingly effective tool that prompts us to continue following a dictate that our parents drummed into our heads: It's your duty to change your oil every 3,000 miles — or your car will pay the price. But as David Langness, a former service adviser, told us, the 3,000-mile oil change is "a marketing tactic that dealers use to get you into the service bay on a regular basis. Unless you go to the drag strip on weekends, you don't need it."

Some car dealers' service departments have been known to incorrectly list the mileage for the next oil change. We've seen them recommend a 3,000-mile oil change on a car with a 10,000-mile interval and a 5,000-mile recommendation on a car with a variable oil change schedule.

Because busy car owners seldom read their owner's manuals, most have no idea of the actual oil change interval for their cars. And so they blindly follow the windshield reminder sticker, whether it's an accurate indicator of the need for an oil change or not. "I just go by the sticker in the windshield," one well-to-do, educated Denver-area Lexus owner told us. "Otherwise, how would I know when to change it?"

A career Navy mechanic who bought an Edmunds long-term car just shrugged when he was told that the vehicle had safely gone 13,000 miles between oil changes. "I'll just keep changing the oil every 5,000 miles," he said. "It's worked well for me in the past."

Our oil-change addiction also stems from an outdated argument that nearly all cars should be serviced under the "severe" schedule found in the owner's manual. But this argument has lost, or at least continues to lose, credibility. A number of automakers, including Ford and GM, once frequently asked Edmunds data editors to publish the normal interval schedule instead of the severe schedule that had been displayed.

Who benefits from more oil changes?

The people who stand to gain from the 3,000-mile oil change are those who work at or own quick-lube outlets and dealership service departments. In their internal industry communications, they're frank about how oil changes bring in customers.

A recent article in National Oil and Lube News, an industry publication, interviewed a Shell technical specialist who offered this advice to quick-lube shop owners: "As the intervals between oil changes continue to extend, it's worth noting that many consumers often neglect to check their vehicle's fluid levels. So, it's beneficial to advise them to bring their vehicles in for a fluid level inspection and top-off every 2,000-3,000 miles."

Another National Oil and Lube News article tied the frequency of oil changes to success in pushing related products and services. The article noted that for a midsize SUV, the stepped-up oil change intervals will bring in $1,800 over the car's lifetime. "A few extra services [or oil changes] can go a long way toward increasing the amount of money a customer will spend during the lifespan we estimated here," the article concludes.

Today's oil goes the distance

While the car-servicing industry is clear about its reasons for believing in the 3,000-mile oil change, customers cling to it only because they're usually unaware of advances in automotive technology. On 2023 and newer models, the majority of automakers either have oil life monitors or call for oil changes 5,000, 7,500, 10,000 and even 15,000 miles based on a normal service schedule. This translates to an average of more than three times the traditional 3,000-mile interval.

"Oil has changed quite a bit, and most of that isn't transparent to the average consuming public," a principal scientist at Pennzoil Passenger Car Engine Lubricants told Edmunds.

Synthetic oils, such as the popular Mobil 1, are stretching oil change intervals, leaving the 3,000-mile mark in the dust. "The great majority of new vehicles today have a recommended oil change interval greater than 3,000 miles," said a Mobil spokeswoman. The company's most advanced synthetic product (Mobil 1 Extended Performance) is guaranteed for a 20,000-mile synthetic oil change interval.

Today's longer oil change intervals are due to:

• Improved "robustness" of today's oils, with their ability to protect engines from wear and heat and still deliver good fuel economy with low emissions
• More automakers using synthetic oil
• Tighter tolerances (the gap between metal moving parts) of modern engines
• The introduction of oil life monitoring systems, which notify the driver when an oil change is required based on the way the car is driven and the conditions it encounters. Today, a majority of the vehicles sold in the U.S. come with such monitors.

Years ago, Edmunds editors drove our long-term Pontiac G8 for 13,000 miles before the monitoring system suggested an oil change. We sent a sample of that oil to a lab for analysis. The results showed that the oil could have safely delivered at least another 2,000 miles of service.

Oil experts and car manufacturers are solidly on the side of the less frequent oil changes that these formulation changes make possible. "If customers always just stayed with the 3,000-mile recommendation, there'd be these great strides in the robustness of oil that oil companies have made [that] wouldn't be utilized," the GM engineer said. Consumers, he said, would be "throwing away good oil."

The environmental effects

Chris Risdon, a product education administrator for Toyota, agreed, adding that advances in oil technology that enable fewer changes help protect the environment. "If you're doing it half as much, that's 5 quarts of oil times 1.7 million vehicles a year. That's a tremendous amount of waste oil that's not being circulated into the environment."

Waste oil is exacerbated by too frequent oil changes, according to CalRecycle, which has campaigned against the 3,000-mile dictate. The agency says that 154 million gallons of used oil are generated in California annually, but only 59% of it is recycled.

There are still hundreds of quick-lube shops that do things the old-fashioned way. Their deep fallback argument in favor of frequent oil changes is that they are a hedge against trouble. You can't hurt your engine by changing your oil too often, so doesn't that imply that it might actually help it? Well, no.

Steve Mazor, former manager of the American Automobile Association's Research Center, said that more frequent-than-necessary oil changes will not "gain any additional life for your engine or any improved fuel economy." He added, "In reality, it will make little or no difference to the performance of the vehicle."

When is the right time to change your oil?

So where does this leave the car owner who was raised on the perceived wisdom of the 3,000-mile, or even the 5,000-mile, oil change? For a full discussion, your next stop should be our related article, "When Should You Change Your Oil?" It will save you hundreds of dollars over the next few years, fully protect your car and its warranty, and help limit the use of a natural resource.

The short answer, meanwhile, is to consult your owner's manual, Edmunds' maintenance guide, or CalRecycle's "Check Your Number" calculator to learn your car's actual oil change schedule. If your car has an oil life monitoring system, don't try to second-guess it. Understand how it works and follow its guidelines. To probe more deeply into this subject, consider sending a sample of the oil from your next oil change to a lab such as Blackstone Laboratories for an inexpensive analysis. Our last suggestion? Rip that sticker off your windshield.