How Oil-Change Intervals Stretched From 3,000 to 10,000 Miles
The rule of thumb has changed due to advances in synthetic options.
Manuel Carrillo III/Capital One
Article QuickTakes:
Oil is the lifeblood of the internal-combustion engine, allowing all the moving pieces to glide smoothly with minimal friction. Back in the day, it was common practice to change a car’s oil every 3,000 miles to keep the engine running at its best, but advancements in oil technology have extended this interval and made car ownership easier.
Why Are Recommended Oil-Change Intervals Longer?
The auto industry has increasingly moved away from lubricating engines with crude oil in favor of full or blended synthetic oils. To make the latter, oil companies chemically process crude oil or petroleum materials to remove their molecular impurities that limit how quickly the oil can flow, which temperatures it can withstand, and how readily it breaks down.
Compared with traditional oils, synthetics or blended synthetics (made of conventional and synthetic oil) tend to have lower viscosities, which means they flow more easily. This minimizes friction between components and thereby extends engine life. Synthetics also resist degradation and the formation of efficiency-killing sludge better than crude oil, so you don’t have to change them as often.
Synthetic oils have existed for about a century, but their development didn’t take off until after World War II, when aerospace engineers needed a high-temperature oil that could protect a jet engine during supersonic flight. In the 1960s, carmakers began to take notice of this better-performing albeit higher-cost lubricant and started using it in specific automotive applications. It has since trickled down into many mainstream vehicles, with about 70% of 2019 models using some sort of synthetic oil.
How Often Should I Change the Oil in My Car?
You need to consult your car’s owner’s manual, which will indicate the recommended oil type for your vehicle and how regularly you need to change it. We strongly suggest you stick to this schedule, as failure to follow these instructions could potentially void your car’s warranty and cause your engine to overheat or suffer internal damage.
In general, though, modern cars can manage 5,000 to 7,500 miles between oil changes. If your vehicle calls for a blended or full synthetic oil, you can push that to 10,000 miles. Old cars (i.e., those that date back to a time before synthetic oils became mainstream) will have relatively short oil-change intervals in comparison.
What Else Do I Need to Consider?
Many modern vehicles have oil-life monitoring systems, some of which rely on information from the powertrain control module while others use sensors to measure actual oil conditions. Either way, such systems can estimate the amount of life left in the engine oil and tell the driver (via an indicator light or message in the instrument panel) when they need to act.
If your car doesn’t get much exercise, you may wish to consider changing the oil based on time rather than mileage. You shouldn’t keep the same oil—whether conventional or synthetic—in your car for more than a year. In fact, some experts advise that you change your car’s oil every six months, regardless of the distance driven.
The more stress you have on the engine, the sooner you’ll need to replace the oil. For instance, if you haul and tow heavy loads or drive in very hot, cold, or dusty climates, your car will likely require more frequent attention, even if the oil is synthetic. Driving short distances (say, less than 10 miles) on a regular basis could also lead to oil breakdown, as the engine (and its oil) may not have adequate time to heat up.
