Synthetic Versus Conventional: Which Motor Oil is Best?

Which motor oil is the best?

As the lubricant for the moving parts of your engine, motor oil is widely considered to be the most important fluid you can use. It prevents excessive engine wear and tear, which makes it vital to keep your car running. So it’s important to understand the different types of motor oil available and how to choose the best one for your vehicle, budget, and needs.

Conventional, synthetic, and blend

There are three main types of oil–conventional, synthetic and synthetic blend. Conventional oil is organic—it’s essentially refined crude oil that’s been pumped up from the ground. Synthetic oil is manufactured molecule by molecule, and because of that, synthetics have fewer imperfections in their chemical buildup than conventional does. Synthetic blends, or “semi-synthetics,” add synthetic additives to conventional oil and can be a nice compromise between the two. They’re less expensive but provide some of the performance enhancement you get from a synthetic.

And…synthetic wins?

In general, synthetic oil outperforms conventional oil on all counts:

  1. Synthetic oil works better in extreme temperatures from below freezing to above 100′ F. Conventional oil is highly reactive to temperatures.
  2. Because synthetics have superior lubrication (they’re more slippery) and create less sludge, so they give you better fuel economy, performance, and even a longer engine life.
  3. And best of all, synthetics don’t have to be changed as often. But make sure you meet warranty service mileage intervals regardless.

The only downside to synthetic oil is it costs more than the regular stuff–typically twice as much. That’s a big difference. But before you choose pennies over performance, crunch the numbers. With longer oil change intervals, the price difference might be a wash. However, if you don’t drive your car hard and/or in extreme conditions, and if you don’t tow heavy loads or supercharge your engine, and if you change your oil promptly on schedule, the price increase to switch from conventional oil to synthetic may not be worth it to you.

Keep in mind…

These three types of motor oil will work fine in your vehicle as long as they meet current American Petroleum Institute (API) certification and don’t go against the manufacturer’s recommendations. The only type of engine you should never use synthetic oil in is a rotary. Rotary engines have unique seals that are engineered for use with conventional oil only.

Pro Tip: Check that you’re not voiding your warranty by using the wrong oil. Many newer vehicles require that you use synthetic oil and some synthetics aren’t approved for certain diesel engines.

The final say

When buying oil for your car, the best thing you can do is to follow your manufacturer’s recommendations. So, check that owner’s manual! When you consider that the wrong oil can cause an engine to fail, it pays to take their suggestions seriously. If you have the option to choose between synthetic and conventional and still aren’t sure which to pick, try a synthetic blend. Still unsure? Consult a pro.

So where do you fall in the synthetic vs. conventional debate? Leave us a comment.

Motor Oil: What Do the Numbers Really Mean?

“220. 221. Whatever it takes.”

That infamous line of reasoning worked for Jack Butler (Michael Keaton) in the 1983 movie Mr. Momso it should work for you, too, when it comes to selecting the right motor oil grade, right? Simply pick a number? Nope! Just like with electricity, when it comes to car oil, numbers matter—especially if you want to protect your engine.

motor oil 1Understanding viscosity

Oil “weights” or grades—such as 10W-30—are actually a numerical coding system developed by the Society of Automotive Engineers (SAE) to grade oils based on their viscosity.

Viscosity is measured by how long it takes a specific amount of oil to flow through a specific-sized opening at a specific temperature. The longer the oil takes to flow through, the higher the viscosity. The tool used to conduct that test is a “viscometer.”

To better visualize viscosity, think of pouring pancake syrup from the bottle. At warmer temperatures, the syrup pours fast and easy, while at colder temperatures, it’s thicker and more difficult to get flowing.

The same can be said for engine oil. Only, the particular challenge with motor oil is that automotive engines need the opposite from their oil. When temperatures are freezing, engines need the oil to be thin and free flowing, not sluggish. But when temperatures rises, engines need the oil to stay thick as the engine reaches operating temperature. That’s where multi-weight or multi-grade oils enter the picture.

What does the “W” mean in oil weights?

American Petroleum Institute

SAE’s J300 standard, first published in 1911 and revised numerous times since, classifies oil into 11 viscosity grades—0W, 5W, 10W, 15W, 20W, 25W, 20, 30, 40, 50, and 60. The “W” signifies “winter,” not weight. Oils first received this “W” designation from SAE in the 1950s. The lower the number preceding the W, the lower the temperature for which the oil is rated.

Those winter numbers were modified further after a rash of catastrophic engine failures in the early 1980s. Unusually cold weather in the U.S. and Europe caused oil to gel. When this occurred, the engine would still start, but it couldn’t pull the gelled oil out of the oil pan, resulting in the failures. As a result, SAE added a low-temperature test to measure pumping viscosity as well, and indicated this oil with the W specification.

The importance of temperature

Back to the idea of multi-weight oils. A popular oil, such as 10W-30, performs like two oils in one when it comes to engine lubrication. At colder temperatures it delivers a 10W-grade oil performance, while at higher temperatures it performs like a 30-grade oil. This provides engine protection at both ends of the temperature spectrum, which is important since engines have to operate in a range of temperatures.

Think of it this way—that SAE 30 oil you might use in your riding mower has the same viscosity as the 10W-30 oil in your vehicle, but only at 210°, the maximum temperature that SAE requires. The difference arises at colder temperatures where the SAE 30 oil can’t perform, necessitating some enhancements that make it a multi-grade oil. At those lower temperatures, that’s where the 10W oil and its characteristics come into play.

Oil’s desired performance characteristics at varied temperatures, as specified by SAE, are achieved through the addition of Viscosity Improvers (VI) or modifiers that increase the oil’s viscosity as temperatures rise. The result is oil that performs and provides engine lubrication no matter what the temperature.

Know what to look for

The good news for drivers is that they don’t need to be an engineer or chemist to know which car oil to use, and they don’t have to change their oil grade whenever the temperature changes. Simply follow the motor oil grade recommended by the vehicle manufacturer for optimal engine protection in all types of weather.

oil sealIt’s important to note that SAE also has a coding system for gear oil, such as the one that’s used in a manual transmission, and that it’s different than the ratings for engine oil. So if there’s a bottle of 85W-140 oil sitting on the barn or garage shelf gathering dust, don’t put it in your engine.

And finally, when choosing an oil, look for one with the American Petroleum Institute “donut” seal on the bottle. It indicates that the oil meets API performance standards.

What kind of oil do you use in your engine? Leave us a comment.

Three Good Reasons to Change Your Own Oil

Life is busy. So you’ll be forgiven for thinking that a discussion about changing your own motor oil seems about as appealing as a lecture from your dentist about flossing more regularly. Why should you take precious time, a limited resource, and spend it changing your own oil? Here are three reasons.

motor oil

1. It’s cheaper

Money is a precious resource for many of us. So, it’s enticing to know that changing your own oil saves you green. Typical cars require four to five quarts of motor oil. You’ll also need a new oil filter to finish the job. Guess how much these items cost at an auto parts store. $40? $50? Good news—you can get out the door for around $20-30 bucks, especially if you take advantage of the regular oil change specials. Cheaper than you thought, right?

Now, you may see a $19.99 oil change advertised at the local quick-lube station, but there are a few problems with that.

  1. First, they tend to use generic, one-size-fits-all motor oil that may not be the best quality. One of the great things about DIY is that you get to buy whatever kind of oil you want.
  2. Second, that cheap oil change and convenience comes at a cost—the hard-sell on all sorts of other services that may be a waste of your money and time.
  3. Third, no one cares about your car more than you do. You’ll do a great job because it matters to you.

In short, you’ll save money changing your own oil and gain peace of mind.


Check out oil change specials for deals on the oil and oil filter to save some cash.

2. It’s easier—and faster—than you think

You can change your own oil using a few basic tools. We can help you choose the best oil for your vehicle and even recycle your used oil. As for time—how much time do you already spend waiting in a crowded lobby for someone else to change your oil? With a little experience, you’ll be able to change your own oil in far less time, without ever leaving home.

3. It helps you avoid larger repairs

Changing your own oil can be just the beginning. While you’re changing your oil and filter, for example, it’s also easy to check the drive and accessory belts, air filter, and spark plugs. That way you can catch simple maintenance issues before they become major repairs or problems. DIYing can be addictive, in the best way. So give the oil change a shot, feel pride in your knowledge, and see if the experience turns into a bridge to more exciting projects down the line.

Have you changed your own oil? Do you have tips to share for making it an even easier project? Share your experience with new DIYers.

The Case for Recycling Motor Oil

If you regularly change the oil in your car, chances are you’ve heard about the importance of recycling used motor oil before. It’s a topic we feel pretty strongly about. That’s why we provide free oil recycling at most of our stores, unless prohibited by law. But maybe you have some questions about why we need to recycle oil in the first place, or what the best way to take care of used oil is. Here are the answers.

Rain gutter Source | Robert Lawton/

Why recycle motor oil?

We’re glad you asked! According to the Environmental Protection Agency (EPA), the oil resulting from a single oil change, if disposed of improperly, could contaminate 1 million gallons of fresh water. That’s enough drinking water for 50 people for a year—or it would be without the oil slick on top. Toxic oil sludge clogs sewers and storm drains and sticks to everything it touches—birds, beaches, pets. Cleanup, as you know from watching any news coverage after a major oil spill, is a costly, prolonged procedure.

What happens to recycled motor oil?

Your recycled oil goes into furnaces to heat homes and businesses or to power plants that provide electricity. It can also be used for marine fuels and even be “re-born” into new motor oil. Re-refined motor oils are just as safe and effective for your car’s engine as fresh oil, and meets all of the same API specifications.

Oil slick on driveway

Source |

But does recycling oil really make a difference?

Yes! It takes 42 gallons of crude oil to produce 2.5 quarts of lubricating oil. Compare that to only one gallon of recycled oil to produce the same 2.5 quarts. Every time you choose to recycle motor oil, you’re contributing to a healthier, cleaner world.

Consider also the difference that recycling motor oil can have on your wallet. Disposing of motor oil improperly is illegal and can lead to hefty fines.

How to recycle motor oil

If you’re tackling oil changes already, congratulations. You’re saving money and getting up close and personal with your vehicle. For those who need a starting point, check out this video and read our step-by-step guide by Advance Auto Parts mascot, Tuxlee.

Before you get started, keep a few things in mind:

  1. Catch every drop. Lay out a tarp and use a drip pan with a built-in spout for easy transfer to a storage container.
  2. Use the correct storage container. Use sealed containers made of a suitable plastic, such as PE (polyethylene), or the original oil container. No milk cartons please.
  3. Don’t mix fluids. Motor oil mixed with other automotive fluids, like windshield washer or brake fluid, can’t be recycled. Also avoid storing used motor oil in containers that once housed other fluids.
  4. Remember the oil filter. Oil filters contain both steel and oil, so they’re perfect candidates for recycling. Punch a hole in the oil filter and let the oil drip into the catch container. Even after draining, the filter can contain as much as 10 oz. of residual oil. So be sure to recycle the filter too.
  5. Store used motor oil in a cool dry place until it can be recycled.
  6. Bring it to your local Advance Auto Parts for recycling.

Recycling motor oil is a small way to make a difference for the environment.

Anything we missed about oil recycling? Tell us about it.

How Often Should You Change Your Oil?

Underside of a car with a rag and bucket on the ground

Source | Bob M~/Flickr

How often should you change your motor oil? Every 3,000 miles, right? Maybe. Maybe not. The truth is that most cars can safely go far more than 3,000 miles between changes. How do you know if your vehicle needs more frequent oil changes? And while we’re on the topic, which oil should you use?

Check your owner’s manual

Much of what you need to know about maintaining your vehicle can be found in your owner’s manual. So it follows that the best way to tell how often you need to change your oil is to consult said manual. If your manufacturer recommends an oil change every 7,500 miles, rest assured that your engine is designed to at least meet those specifications.

Know thyself—or at least thy vehicle

As important as knowing how often to change your oil, is knowing which oil to use. Consider the following:

  1. Know your viscosity.Viscosity is that funny combination of numbers and letters you see on a bottle of engine oil. 5W-30 is a common one; so is 10W-40. It basically refers to how easily the oil flows at different temperatures. Consult your owner’s manual for the recommended viscosity.
  2. Know your car’s oil capacity. Find the page in your manual where oil capacity is specified. It will probably be in the neighborhood of five quarts, although some specialized engines can take eight or more.
  3. Choose a quality engine oil. You should only use motor oils with the American Petroleum Institute’s seal of approval. You might also want to read up on the benefits of synthetic oil. And if you decide to have a professional change your oil, don’t be afraid to bring your own oil. That’s the best way to ensure that a high-quality product is keeping your car’s heart beating.

Do you change your own oil or leave it up to a mechanic? How often do you change your oil, and do you use synthetic or conventional oil? Leave us a comment.

Checking Your Vehicle’s Essential Fluids and Hoses Provides Peace of Mind

hood up fixing car

Benjamin Franklin once said, “An ounce of prevention is worth a pound of cure.” The same is true for your vehicle, especially when it comes to its essential fluids and hoses. Regular maintenance checks of these items will contribute to the sustained health of your vehicle and reduce your risk of unpleasant automotive surprises down the road. But where to start? Here are a few things to keep in mind.

Essential fluids

High operating temperatures for your car, particularly during seasonal travel, mean more use of your air conditioner and an even stronger need to keep your engine well lubricated with enough coolant and oil. All fluid checks should be done while your engine is cold. This is VERY important because hot fluids can burn you.

All fluid checks should be done while your engine is cold. This is VERY important
because hot fluids can burn you.

  • Coolant: To check your coolant, unscrew the radiator cap and make sure the level is where it should be according to the line on the tank. If you’re low, topping off with a pre-mixed 50/50 coolant will save you time and fuss.
  • Motor oil: To check your oil, pull out the dipstick, wipe it down with a rag, and stick it back in. When you pull it out again, the oil should be at or above the line marked on the stick. If it’s too low, add a quart. Your owner’s manual will tell you what kind you need.
  • Windshield washer fluid: While you’re at it, check your windshield washer fluid. Your car may be able to survive without it, but a clear view of the road can be a life saver—literally. In most vehicles, washer fluid is blue and housed in a white plastic tank. Look on the side of the tank or open the cap covering the tank to check the fluid level.

For more helpful tips on checking essential fluids, read this.

Radiator hoses and spare tires

Fluids aren’t the only things that keep your vehicle running smoothly. Include these items in your regular inspections.

  • Radiator hoses: If coolant is the life blood of your engine, then radiator hoses are the arteries. So, while you’re under your hood, check your radiator hoses for leaks or wear. Squeeze the hoses and make sure they’ve got some give to them. If they’re hard and brittle or cracked, they should be replaced. It’s an easy job and far preferable to breaking down on the side of the road when you’re headed out to the lake with the family.
  • Spare tires: As long as you’re taking stock of your vehicle’s essentials, you may as well check your spare tire. First, make sure you have a spare tire in your car. Many vehicle manufacturers these days are eliminating spare tires as a standard feature. If you have a spare tire, make sure it’s properly inflated. Don’t forget to keep a tire iron in your trunk, along with any other equipment needed to change a tire by the side of the road. You can read through your owner’s manual to get a feel for what it takes to do the job. If you don’t have a spare tire on your vehicle, consider carrying a tire repair kit.

Many vehicle manufacturers these days are eliminating spare tires as a standard feature.

Checking the fluids and hoses on your vehicle will save you money and hassle. They’ll also give you something you can’t put a price on: peace of mind. Are there easy hose and fluid checks you perform on your vehicle? Leave us a comment.