Can You Use Regular Oil After Synthetic & 4 Other Oil Myths Answered

Decades ago, the comparison between synthetic oil and conventional oil started, and surprisingly, it is still going on. From automobile professionals to popular oil manufacturers to consumers, everybody has a difference of opinion related to this subject.

As a result, the internet is loaded with confusing questions like “Can you use regular oil after synthetic? or “Why can’t you go back to regular oil after synthetic? But the answers to these questions are still not clear to many drivers out there.

Therefore, we decided to shed some light on these queries regarding synthetic oil and conventional oil with logical reasoning. But before we jump into the article, let us give you a brief description of each oil, so that you can understand the concept better.

Conventional oil, also known as regular oil, is mostly used in older vehicles. It is an age-old engine oil that comes from the natural purification of crude oil. On the other hand, synthetic oil is a man-made creation that is suitable for modern engines. The advancement of high-quality additives used in synthetic oil has earned massive appreciation.

Each oil has its own speciality, which sets them apart. So now let’s dig in and clear out some of the misunderstandings related to them.


  • Can You Use Regular Oil After Synthetic?

    Can You Use Regular Oil After Synthetic

Yes, you can use regular oil after using synthetic oil. Many believe that once you start using synthetic oil, it becomes difficult for an engine to adapt to regular oil. But it is a misconception. Modern engines are engineered to work well with both regular oil and synthetic oil. As long as you are willing to let go of the more advanced benefits of synthetic oil, you can use regular oil for basic protection and function.

In fact, regular oil is adequate for people who use their vehicles for basic commuting. Moreover, for anyone looking for budget-friendly engine oil that fulfils the basic requirements, regular oil is your best choice.

Furthermore, for older vehicles with high mileage whose pistons are thinner and worn-out, regular oil is a better option than synthetic oil.

So, next time when someone asks, “Can you go from synthetic oil back to conventional oil? Remind them of these benefits of switching over to conventional oil. But before you change your oil, you must keep a few aspects in your mind.

Firstly, make sure your engine seals are in proper condition because if the condition of your current engine is not up to the mark, then, conventional oil may do more damage than good. Secondly, always check the viscosity grade required for your vehicle and choose the regular oil that matches the criteria.

Having said that, many automobile experts have given some reasons concerning why can’t you go back to regular oil after synthetic. It’s mainly because the engine doesn’t run that smoothly with regular oil as it does with synthetic oil.

So, with conventional oil, you may have to listen to the annoying grinding sound from the engine while driving. Furthermore, you may also notice poor gas mileage as the engine exhausts easily with regular oil.

Nevertheless, if you don’t have the budget or simply don’t require the added advantages of synthetic oil, you can go back and forth between regular and synthetic oil easily.


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  • What Happens If You Use Regular Oil Instead Of Synthetic?

    What Happens If You Use Regular Oil Instead Of Synthetic

Synthetic oil was formulated to meet the increasing demands of modern engines. So the difference between using regular oil instead of synthetic will be huge, to say the least.

To begin with the good points, both regular oil and synthetic oil contain almost similar additives. That is why regular oil is also capable of performing the basic function, i.e., lubricating the engine very well.

Also, as discussed earlier, regular oil provides better protection for older vehicles as they require a moderate flow of engine oil. Not to forget, it is good for your wallet too.

Apart from this, using regular oil rather than synthetic will only lead to distress. For instance, regular oil doesn’t operate very well under extreme temperatures, be it cold or hot.

At low temperatures, it gets thick and hinders the quick start of the engine. Similarly, it overheats rapidly during harsh summers.

Moreover, new engines, like turbocharged, may get damaged due to the excess deposit that gets collected because of the slow fluidity of regular oil. Consequently, this will shorten the cycle of your oil change intervals as it cannot resist thermal degradation sufficiently.

Also, if you choose regular oil over synthetic oil, you will be missing out on so many advantages. Synthetic oils are laboratory-made engine oils that are much more refined than regular oil. Thus, most manufacturers would recommend you to use synthetic oil as it provides advanced engine protection against CO2 emissions and saves engine power to a greater extent as compared to regular oil.


  • Can You Mix Synthetic Oil With Conventional Oil?

    Can You Mix Synthetic Oil With Conventional Oil

From a broader perspective, yes, you can mix synthetic oil with conventional oil as both are highly compatible. But be aware that it should be done rarely and only for short-term because the difference in the characteristic of the their additives may reduce the overall engine performance.

Also, there are a few points to remember while you perform this task. The viscosity of both the oils should correspond to each other. Also, avoid mixing a cheap quality oil with superior quality oil, be it synthetic or conventional. For a better solution, do check out our pro-tip ahead.

Moreover, whether this mixing can damage your engine or not depends on how often you do it. If it’s a case of emergency, there is probably no harm in mixing a portion of conventional oil with synthetic oil and vice versa.

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However, doing it frequently may hinder the smooth functioning of your engine. The reason behind this is that even though both synthetic and conventional oil carries similar base oil and additives, synthetic oil has fewer contaminants and advanced detergents. Therefore, the continuous mixing of low-grade oil and premium oil can mess up the engine.

Pro-tip- To get the benefit of both synthetic and conventional oil, you should buy a premium quality synthetic blended oil instead of mixing them on your own. These blended oils are prepared by experts, so you won’t have to worry about the damage caused by incorrect viscosity and quality.


  • When To Switch To Synthetic Oil After Break-In?

This is also one question that motorists often worry about. Based on our detailed study of the technical engine’s break-in process and the user’s opinion, we can say that synthetic oil should be used after the completion of the initial stage of the break-in process. In the beginning, using conventional oil would be a wise choice.

For the proper break-in of the engine, the seals between the piston rings should attach to the cylinder walls appropriately. During the break-in process, conventional creates the necessary friction for the moving parts to settle down for better performance.

Synthetic oils are known for their slippery texture, which reduces the wear down of all the parts properly. So it is advised by the experts to use conventional oil for at least two initial oil changes, which means till the vehicle completes at least 1000 miles.

Then, later on, simply drain the oil, withdraw the filter, and fill the engine with synthetic oil. That being said, many famous oil brands, like Mobil 1, claim that new engines do not need the break-in process, so they usually arrive with factory-filled synthetic oil.

In that case, you should change the factory-filled synthetic oil as recommended by your manufacturer’s manual.



Taking the right decision concerning engine oil has never been easy because of the conflicting opinions given by our predecessors. But with every new development, the prior statements regarding synthetic oil and conventional oil are now nothing more than myths.

For various reasons, synthetic oil has an upper hand over regular oil. However, this does not mean that regular oil should be dismissed completely.

Apart from gaining information from the internet, you should always evaluate your vehicle’s manual. No one knows what’s good for your engine more than your manufacturer.

But if you want to experiment with either of the engine oils, learn as much about the oil as you can. Hopefully, we have helped you in some ways and clarified some misconceptions.