The Facts About Changing Car Engine Oil

| July 16, 2012

getting an oil changeVisit any auto parts store — DexKnows auto parts stores listings is a good place to find one — and you’ll see shelves of engine oil, but how do you know what your car needs? Let’s run through some facts about changing engine oil.

What’s oil for?

Oil helps metal surfaces slide over each other. Without oil, friction creates heat and the surfaces begin to stick together. After just a few minutes of this, the engine seizes up completely. Oil has a second role too: as oil-manufacturer Castrol explains on their website, engine oil provides a lot of cooling.

Why should I get it changed?

Oil picks up dirt and metal from inside the engine and even though a filter removes most of it, some stays in the oil. Over time, heat, pressure and traces of gasoline break down the oil molecules, and this gritty, old oil is not very effective.

Most of us were told to get our oil changed every 3,000 miles. That’s not wrong, but evidence suggests that that might be more than necessary. Read “Stop Changing Your Oil” and “When Should You Change Your Oil?” on auto specialist website Edmunds.com to get a better understanding of this topic.

Since modern engine oils last longer, many car manufacturers today recommend oil change intervals of 7,000 miles or more. On the other hand, the way you use your car affects oil life. A vehicle making lots of short journeys should probably have more frequent oil changes, so read the handbook or talk to the dealership service advisor.

Is all oil the same?

No, but you can’t tell just by looking. To get around this, the American Petroleum Institute (API) introduced their “Starburst” certification. You’ll find this label displayed on all quality engine oils.

A second label provides the SAE viscosity grade, sometimes called the “weight.” Modern engine oils have two numbers for viscosity, such as 5W-30 or 10W-40. The first number indicates the cold viscosity, (W stands for winter), and the second number the hot viscosity. Low viscosity in cold conditions makes it easier for the starter to spin the engine. Then again, if the oil gets too thin when warm, metal surfaces could touch. Which grade is right for you? Check the handbook for your vehicle or ask at your local auto parts store or your mechanic.

Modern “synthetic” engine oils offer improved life and performance, but there’s debate as to whether they’re suitable for all engines. Valvoline and other oil companies provide advice about synthetic oil on their websites.

Who should change my oil?

An oil change can be done at home. It takes an hour or less, avoids a trip to the repair shop or dealership, and might save a few bucks. But just because it can be done at home, it doesn’t follow that it should. In fact, there are good reasons for having your oil changed at your local oil change location, auto repair shop or dealership.

First, used engine oil must be disposed of properly. That means taking it to an appropriate drop off site — most cities provide them at little or no cost — or to an auto parts store equipped to handle used oil.

Second, used oil may be carcinogenic: you really don’t want it getting on your hands, clothes and garage floor, or have your children or pets near it.

For these reasons, many car owners prefer to get their oil changed at an auto shop or oil change center. Check the DexKnows auto repair shop listings for one close to you.

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Category: Auto Maintenance, Autos, Evergreen

About the Author ()

After twenty years in the automobile industry the craft of wordsmith called. Putting down the wrench, Nigel picked up a keyboard on which to express his passion for all things automotive.