For decades, the common wisdom was simple: if you care about your car, you change the oil every 3,000 miles. This practice has been handed down from one generation to the next since Cadillacs sported giant tail fins. But automotive technology has advanced tremendously since then, rendering 3,000-mile oil changes obsolete in all but a handful of cases.
In this article, we will explore how improvements in modern engine construction and oil formulation over the last two decades have extended oil service intervals, with some manufacturers now advising as many as 15,000 miles between changes. Understanding these developments and how they apply to your car is key not only to keeping your engine in good health, but it can also save you big bucks on maintenance. It's better for the environment, too.
The Importance of Changing Your Oil
Before we look at why oil change intervals are growing longer, let's talk about why your car needs them in the first place.
Oil plays four key roles in the performance of your engine. First and foremost, it provides lubrication for the many moving parts inside, reducing friction and wear. As it circulates, oil also redistributes heat, assisting the cooling system in maintaining the engine's optimal operating temperature. Third, oil helps keep the engine clean inside by picking up carbon and other leftovers from the combustion process; these then get sifted out by the oil filter. Finally, oil protects the engine's internals against rust.
But with time and use, oil breaks down and loses its effectiveness in performing these essential functions. That's why changing both your oil and oil filter at regular intervals is such an important maintenance task. Failing to do so can lead to a long list of expensive problems, including premature wear, overheating and even engine failure.
Improvements in Engine Technology and Oil Quality
Unlike the cast-iron V8 in your great grandad's Coupe de Ville, modern engines benefit from computer-aided engineering and advanced materials that keep internal friction to a minimum, even under extreme conditions. Their tighter tolerances and more efficient designs result in less contamination and a slower breakdown of oil over time.
Likewise, the technology used in making motor oil has evolved significantly in recent decades. In particular, the development of synthetic oil, first popularized in the 1990s, has dramatically increased both its effectiveness and longevity. Similar advancements have occurred in conventional motor oils, too.
These new oil formulations maintain their viscosity and protective properties over much longer periods than before. They're also more effective at resisting high temperatures, preventing sludge buildup and protecting against engine wear.
New Oil Change Standards
As a result of these advancements, car manufacturers now recommend oil change intervals that are significantly longer than the old 3,000-mile benchmark. In fact, most automakers now recommend oil changes every 5,000 to 10,000 miles. Some even stretch it to 15,000 miles or more.
To find out what's right for your car, check the owner's manual. It provides not only the recommended oil service interval but also the proper type of oil and filter to use.
In the manual, you'll likely find guidance for both "normal" and "severe" driving conditions. The latter applies to those who take frequent shorter trips or do heavy-duty work with the vehicle, such as towing. Since this is harder on the engine, "severe" oil change intervals tend to be shorter. But for the vast majority of drivers, the "normal" interval applies.
Modern vehicles are also equipped with monitoring systems that alert you when an oil change is necessary, taking into account factors such as time, miles and driving conditions. If your car has one, it's your best guide.
The Benefits of Longer Intervals
Despite these developments, some people stick with 3,000-mile oil changes because, they say, it's cheap insurance. After all, an oil and filter service is among the least expensive automotive maintenance tasks. But the costs add up over time, and they're not just monetary.
Let's take a 2020 Toyota RAV4 for example. Adhering to the manufacturer's recommended 10,000-mile oil service interval, it would undergo 20 oil and filter changes in a typical lifetime of 200,000 miles, requiring about 100 quarts of oil in all. That more than triples to 67 changes and 335 quarts when changing the oil every 3,000 miles. In this case, sticking with the manufacturer's recommendations saves you thousands of dollars in oil alone, not to mention all those hours spent servicing the car and the need to dispose of nearly 50 additional oil filters.
Doing fewer oil changes also reduces your overall consumption. At first glance, it may not seem like much, but consider that Toyota sold 10 million RAV4s worldwide by 2020. If all of them used the automaker's recommended interval instead of the old 3,000-mile standard, it would save over two billion quarts of oil over the lifetime of that one model. It would also mean generating that much less waste oil to be disposed of.
Final Thoughts
Thanks to major advancements in engine design and oil formulation, the era of 3000-mile oil change intervals has faded into the rearview mirror. And that's good news.
Ditching that outdated standard and adhering instead to the manufacturer's recommended service interval means you can keep your car's engine in excellent health while saving money and time. It also reduces both consumption and waste, making a path towards more sustainable car ownership.
You may get contradictory advice from the local oil change center. But just keep in mind that their business is to sell more oil changes. Stick with the manufacturer's guidance instead. It's better for your car, your bank account and the environment.