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What Does Oil Life Percentage Mean?

oil life percentage

One of the most basic ways to keep your engine healthy is by changing the oil on a regular basis. But the amount of time between oil changes is no longer set at the standard 3 months or 3,000 miles. So what’s the best way to determine your oil life percentage and find out when to change your oil? Between your odometer, a specialized system on your vehicle and the type of oil you use, it’s easy to calculate your oil change interval.

Take a LookScroll through your vehicle

Inspecting the engine oil sample at the end of the dipstick was once a common method for evaluating if the engine oil needed to be changed. Though it’s important to check your oil periodically, a visual inspection is not the most accurate way to assess if your oil is reaching the end of its usefulness. This is partially because color is no longer a clear indicator due to the additives many oil manufacturers use.

Oil Lifespan

Another common method is to track your vehicle’s mileage. The lifespan of an oil depends on its type and brand, but you can use the mileage recommendations to help plan your next oil change.

Engine oil lifespan varies depending on the oil category and the brand. To estimate how long it will last, check the label on the oil container. Then, select the engine oil that best fits your vehicle and your budget from one of the four basic types:

Conventional oil

This standard engine oil is the most common, the least expensive and is a suitable option for many vehicles. Conventional motor oil typically lasts about 4,000 miles or four months.

Synthetic oil

Synthetic oil is often used in high performance vehicles and can last between 10,000 and 25,000 miles, depending on the oil.

Semi-synthetic oil

Also called a synthetic blend, this type offers some of the advantages of a synthetic oil at a lower price, which makes it a favorite for many truck and SUV drivers. Lifespan varies depending on the blend mixture and brand.

High-mileage oil

This type of oil is created for vehicles with 75,000 miles or more. Lifespan on this type of oil will vary, so be sure to check the label.

Whether you select a conventional oil or a specialized blend, make sure you schedule a reminder for the next time you need to change your oil. Oil thickens as it ages, so it can get weighed down with debris and contaminants. This compromises its ability to effectively lubricate and maintain your engine.

Follow the recommended guidelines for your oil blend or refer to your vehicle’s oil life monitoring system to correctly plan your oil change intervals.

Check out all the chemical products available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on types of engine oil and oil life percentage, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

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Sarah Shelton View All

As a freelance automotive writer, I create articles, how-to guides, web content and white papers for online magazine site and automotive companies. I passionately believe that cars and motorcycles should be appreciated for the works of art they are, and fantasize about owning a white Ducati 899 Panigale to display in my living room. I am currently the Corvette expert at, cover alternatively-fueled vehicles and technology at, and hold the imaginary title of Formula One test driver on the back roads surrounding my Oregon home.

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