The Advantages and Disadvantages of Conventional Oil

Many technicians will tell you that conventional motor oils are outdated and you should switch to synthetic oil. But this insistence may leave you wondering if that’s really true. What actually are the advantages and disadvantages of using conventional oil?

Although it’s true that synthetics can perform better in many situations, conventional oils can still have their uses. It all comes down to the age and make of your car and what you’re looking for in your oil.

Read on to learn more about the pros and cons of conventional motor oils.

What Is Conventional Motor Oil?

Before we get into the advantages (and disadvantages), you need to know what kinds of oils we’re talking about. 

After all, what exactly makes motor oil “conventional?”

Conventional motor oil — also called mineral oil, regular oil, or traditional oil — is an oil product used in car engines. Its purpose is to lubricate and protect engine parts, preventing excessive wear and ensuring the smooth operation of the engine. 

Without motor oil, your car engine would quickly grind to a halt or break.

Traditional motor oils are produced by refining crude oil. To explain the process simply, manufacturers heat crude oil until it leaves behind a heavier petroleum oil product. This heavy oil serves as the base material for motor oil, into which manufacturers add certain additives to improve its performance characteristics.

Full synthetic oil, on the other hand, doesn’t use crude petroleum oil as the base material. Instead, they’re manufactured around an entirely artificial oil. This gives synthetic oils a more uniform molecular structure which improves their performance.

Finally, there are synthetic blend oils. As the name implies, these products are a mixture of synthetic and conventional oil. Manufacturers produce them to keep costs low while still providing better oil performance.

The Advantages of Conventional Oil

Some technicians might insist that synthetics are better than conventional oils in every possible way. Synthetic oil does have many perks, but conventional oil nonetheless has its own unique upsides. Here are the most significant advantages of using conventional oil.


Conventional oil is much, much cheaper than synthetic oil. This alone is an overwhelmingly positive thing for many drivers.

Synthetic oils can cost anywhere from two to ten times as much as conventional oil. Naturally, that means you’ll have to pay a lot more when you get an oil change. Although synthetics can result in cost savings in the long run, the initial high price is not something you should ignore completely.

The reason behind the price difference is the level of refinement. Although conventional oil is a refined product, synthetic oils are refined and processed to a higher degree. As a result, manufacturing them takes more time and money, and the manufacturers have to make up for the higher production costs.


Another point in conventional oils’ favor is that they’re very easy to find. You can reliably expect every auto repair shop and garage to have a conventional motor oil option that works for your car.

These days, most new cars roll out of the factory with synthetic oil in their engines, but it wasn’t always so. In fact, oil manufacturers started introducing synthetics to the popular market only around 30 years ago.

Before that, nearly every car — with the exception of heavy-duty or high-performance vehicles — used conventional motor oil. And conventional oils still work fine in modern cars, so you can always count on finding a suitable traditional oil.

Better for Old Engines

As we just mentioned, conventional oil used to be the standard engine oil for personal vehicles. Car manufacturers build their engines specifically to work with traditional motor oils.

If your car was made before 2000 or so, it’s highly likely that its engine is intended to use conventional oil. Older engines aren’t as compact as modern ones, so conventional oils can easily flow through them to provide lubrication and protection.

Additionally, if your engine is past its prime, it may not benefit much — if at all — from the perks of synthetic oils. Adding synthetic oil to a 30-year-old engine can cost you a lot more while giving you practically nothing in return.


Your car may already have conventional oil in it — especially if it’s an old vehicle. If you’re not having any performance issues, swapping to synthetic oil may simply not be worth the hassle and cost.

Synthetic oils can extend the lifespan of car engines significantly. But if your engine is already a few years away from retirement, even the best synthetic oils won’t make it last any longer.

In this kind of situation, you might as well keep using conventional oil. 

The Disadvantages of Conventional Oil

Conventional oils can be advantageous in certain situations. That said, synthetic oils simply offer better performance than traditional ones. Due to their artificial nature, oil manufacturers can fine-tune synthetics to simply do things better than conventional oils.

When compared to synthetics, conventional oils have these disadvantages.

Less Engine Protection

Most conventional oils have a higher viscosity than their synthetic counterparts. The consistency of the base oil used in traditional motor oils isn’t as consistent in molecular size as that of synthetics. As a result, conventional oils can’t protect your engine as well.

Modern engines are very compact and have thin, narrow oil lines. High-viscosity traditional oils may not flow properly throughout the entire engine. They may also not coat parts properly, causing them to have increased and uneven wear.

Poor Heat and Cold Resistance

Both hot and cold weather can have a strong negative impact on motor oil quality. In cold conditions, conventional oil becomes more viscous and your car takes a longer time to circulate it through the engine. Without proper lubrication, your engine parts could get damaged.

On the other hand, hot weather can cause traditional oils to evaporate and degrade. This can lead to insufficient oil levels, which will also cause excessive part wear.

Synthetic oils resist extreme temperatures on both ends of the scale better than conventional ones. As such, they may be a better choice in northern Virginia, where the summers are hot and winters freezing.

Higher Oil Consumption

Since conventional oils degrade faster, they will not stay in serviceable condition as long as synthetic oils. If you use conventional oil in your car, you will most likely have to get an oil change more often than with synthetics.

This is an important factor when deciding if swapping to synthetics will be worth it. If changing conventional oil often would cost more than the initially high price of synthetics, it may be worth switching over.

Lower Fuel Mileage

The more work your car’s engine does, the more fuel it will consume. The high viscosity and poor cold weather performance of conventional oils will force your car to put in more work than necessary to circulate oil through the engine.

As a result, the mileage you get out of one tank of gas will be lower than with a comparable synthetic oil. Not only will the poor oil circulation wear engine parts down, but you’ll also pay more at the pump.

Higher Emissions

The lower fuel efficiency of conventional oils doesn’t just cost you money in gas — it also produces unnecessarily high levels of emissions. The more fuel you burn, the more gasses and pollutants your car belches into the air. Synthetic oils can help you consume less fuel and result in lower emissions.

Additionally, conventional oils leach contaminants and water from the ambient air. These contaminants can combust in the high heat of your engine, degrading the oil and further increasing engine emissions. Synthetic oils stay clean longer and can help cut engine emissions as well.

Conventional or Synthetic: Which One Is Right For Your Car?

So, which should you choose — conventional or synthetic oil? There’s no simple answer, and both oils can perform adequately in both old and new vehicles.

As a general rule of thumb, your car’s age may be a good indicator of whether or not you should switch to synthetics. If you drive an old car that is closing the end of its life, you’re probably better off sticking with conventional oil. Your senior vehicle won’t have time to get much out of the benefits of synthetics, so conventional oils’ lower price may save you money.

But if you drive a new car, you may want to choose synthetics instead. Their superior performance characteristics can help extend your engine’s service life and get you more miles out of the car. And even though you may pay more for the oil, you’ll save money in the long run since your car will need less maintenance.

Quick and Reliable Oil Change in Chantilly and Warrenton, VA

It’s particularly important to make the right oil choice in northern Virginia. Our summers are hot and humid, while in the winter, ice and snow are regular guests. These varying conditions can quickly degrade motor oil.

Advanced Automotive has provided oil changes for drivers in Chantilly and Warrenton, VA, for more than 30 years. Our ASE-certified technicians are familiar with all vehicle makes and models and will change your oil quickly — whether conventional or synthetic.

We also offer a free courtesy check with every oil change. You’ll get honest, no-pressure advice on what kind of motor oil is the best for your car. You can then ask us to pour in conventional or synthetic oil, whichever you prefer.

Book an oil change appointment online today. You can also call our Chantilly location at (703) 783-1409 and our Warrenton shop at (504) 353-6435.