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What Is Engine Oil? Everything You Need To Know

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Engine oil plays a vital role in maintaining your car’s engine components. 

It keeps things moving smoothly and impacts the overall performance of your car. 

But what is engine oil

And what does it do? 

In this article, we’ll discuss what engine oil is, what it does, and highlight the different types of car engine oil available. We’ll also help you identify when your car needs an oil change

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Let’s get right into it!

What Is Engine Oil? 

Engine oil, engine lubricant, or motor oil; it goes by many names. 

But it serves one important function — to ensure the smooth functioning of your car’s engine. 

Traditionally, it’s a mix of base oil and certain additive compounds that serve a variety of purposes. It can help lubricate engine parts, cool down the motor, clean and contain dust contaminants, reduce friction, and protect against excessive engine wear and tear. 

However, modern engine oils also help with engine performance and fuel economy. 

It’s one of the reasons why we now have synthetic blend and synthetic engine oil.

But what do they do? Let’s take a closer look.

What Does Engine Oil Do?

Motor oils previously served a single purpose — lubrication of engine parts. However, modern engine oils do so much more. 

Modern engine oils are made using oil additive compounds and dispersants such as detergent, antioxidant, viscosity index improver, corrosion inhibitor, friction modifiers, and antiwear additives. 

These additive compounds serve several purposes. 


You now know what engine oil does. Let’s take a look at some common types of engine oil, namely, conventional oil, synthetic blend oil, and synthetic oil.

4 Types Of Engine Oil

Motor oil has advanced over time, and it’s no longer just a mixture of base oil and engine oil additive compounds and dispersants. 

Let’s see how these motor oils have evolved: 

1. Conventional Motor Oil 

Conventional oil, also known as mineral oil, is the standard motor oil manufactured from raw crude oil and then refined in a factory. 

It tends to be less refined than its alternatives and does not provide adequate protection against varying engine temperatures. Its primary function is to act as a lubricant for your engine components. 

However, it is the cheapest among the others.

2. Synthetic Engine Oil

Synthetic engine oil is entirely factory-made and is, therefore, a lot more consistent. 

It is highly refined and is better suited for your car. 

Not to mention, it’s also stable under most engine temperatures and has a high viscosity.

Synthetic engine oil is a highly lubricating oil that protects your engine components and delays any wear and tear. 

But, it is also reasonably higher in cost

3. Synthetic Blend Oil

Synthetic blend oil is also commonly known as synthetic blend motor oil. 

As its name suggests, it’s manufactured from both crude oil and synthetic ingredients. 

This type of oil combines all the advantages of conventional motor oil and synthetic motor oil while trying its best to limit the drawbacks. 

Synthetic blend oil also contains viscosity modifier additives to maintain the oil viscosity under changing temperatures.

It’s more affordable than synthetic oil and a little costlier than mineral oil

4. High Mileage Oil

High mileage oil is carefully formulated with a unique blend of additive compounds that help reduce oil burnoff. It is designed specifically to prevent oil leak problems in older, higher-mileage vehicles. 

If you have an older vehicle or have more than 75,000 miles on your car, you may want to switch to high mileage oil.   

But how do you tell when your engine needs an oil replacement? Let’s find out.

5 Signs That Your Car Needs An Engine Oil Change

Engine oil plays a crucial role in your engine, and it needs regular maintenance and refills to keep working smoothly. 

Regardless of how your motor oil was made (from crude oil or synthetic sources), you will need to eventually change it.

Here are the signs that your engine needs an oil change: 

1. Excessive Engine Noise

A noisy engine is a clear indicator that your engine oil is in desperate need of changing or replacing. 

A well-lubricated engine will never produce a lot of noise. 

However, friction between the parts will create rumbling and knocking sounds when it runs low on oil. This usually means that your engine parts could do with an oil change for a new layer of lubrication.

2. Smell Of Oil

If you smell a strong odor of oil inside the vehicle, it could be an oil leak. 

It’s also possible that your engine’s motor is overheating itself due to old engine oil that has stopped doing its job. 

The best step here would be to check for an oil leak first, and then get an oil filter replacement and oil change. This would also prevent your car from unnecessarily burning oil in the future.

3. Exhaust Smoke

It’s normal for car engines to emit translucent, odorless vapor from the car’s tailpipe. 

However, if this vapor has been turning into smoke, it’s an indicator to pay attention to your engine. 

Check the car’s oil level to check whether it needs an oil change. 

A good idea would be to check the oil viscosity to make sure the oil is still good. Replace it if needed to prevent any potential problems with the engine components.

4. Darker Oil

Multigrade oil (typical car oil) is supposed to be translucent in appearance with a brown hue to it. 

Oil that has gone muddy and looks very dark or blackish in appearance has been contaminated with dust and dirt. Over time, the oil’s viscosity reduces and it’s no longer a very lubricating oil. It’s a good idea to get an oil change at this point.

5. Increased Engine Wear

The average oil change interval for conventional oil is around 3000-5000 miles. Modern engine oils like synthetic motor oil may even go as high as 7000-10,000 miles.

You should determine an oil change routine depending on whether you’re using synthetic oil or traditional mineral oil, and how many miles you plan to use. In case you use up too many miles in a month, it is best to change your oil filter and adjust the oil level.

So how do you decide between the different oils for your car?

How To Pick The Right Motor Oil For Your Car?

The market offers tons of engine oil varieties to choose from, which can be confusing at times. 

You want to select one that has engine oil additive compounds and dispersants such as antioxidants, viscosity index improver, viscosity modifier, friction modifiers, and detergents.

Choosing the right engine oil for your car’s engine will make a great difference in its oil performance and fuel economy. Additionally, engine oil that’s suited to a gasoline engine won’t necessarily be good for a diesel engine. 

Your best bet is to consult your car’s engine manufacturer manual about your oil needs. 

You can also ask a mechanic, and they should be able to help you. 

In this case, AutoNation Mobile Service is the answer! 

AutoNation Mobile Service is a convenient mobile mechanic repair and maintenance solution, and their ASE-certified mechanics can handle your engine oil changes right in your driveway. 

For a quick, accurate estimate of how much it may cost, just fill this online form.  

Final Thoughts

Quality engine oil is a good investment for your car, as it provides some much-needed TLC to the engine parts. 

That’s why it’s always important to follow a regular oil change schedule.

And when that time comes, think AutoNation Mobile Service
With AutoNation Mobile Service, you get the best possible car repair and maintenance services, and competitive and upfront pricing. This way, your car’s always in perfect shape!