Can You Use Regular Oil after Synthetic Oil?

by Chris Lewis.

There are a lot of myths and misconception surrounding this particular question. One party argues with the biblical allusion that “you can’t put new wine into old wineskin.” They back their argument with the superiority synthetic oil holds over regular oil- Which is why they see the switch up as quality degradation.

The other group simply argues that oil is oil regardless of the type. Since they all contain the same compounds only that one has the best, a switch over is not a bad idea at all. That puts most car owners in a fix when it comes to making this decision.

So to settle this tiny dispute, let’s shed some light into the right answer.

Is It Possible to Switch Over?

Is It Possible to Switch Over?
Is It Possible to Switch Over?

Yes, it is very possible to shift from using synthetic to regular. The change has no effect on your car’s well-being whatsoever. The oil still plays its role in the engine. The notable effect and difference arises from the engine performance.

Synthetic oil is miles away from the regular when it comes to quality assurance. That is not a myth but a proven fact. In that case, once you make the change, a steady decline in your engine performance will be the end result.

However, this point gets misinterpreted and gives breakthrough to misconceptions that a switch is not possible. Remember only your engine’s performance gets affected. Though experts would recommend you stick to only one type of oil, preferably the synthetic.

Look at it this way. Assuming you stick to a healthy diet for like three months. Your body’s general health and performance will be on point. Then all over sudden you change your diet to mainly junk foods for another three months. You’ll definitely feel the effect and of course it won’t be a positive one.

To get a better grasp at the performance effects of the oil change, let’s check out the differences between the two types of oil.

Contrast between Regular and Synthetic oil

Contrast between Regular and Synthetic oil
Contrast between Regular and Synthetic oil

Mileage and Lubrication

The breakdown for the regular oil is higher than the synthetic. Regular oil can’t hold on for more than 3,000 miles. The synthetic oil on the other hand kills the game when it comes to mile coverage. The best synthetic oil brands can go for up to 25,000 miles before an oil change.

The effect of switching from synthetic to regular is already obvious. You’ll become a regular visitor at the garage. The friction resistance capabilities of both oils factor in also. Synthetic oil is by far a better friction resistor than the regular.

Once you pick the regular oil for your engine after the synthetic, well it won’t be exactly the same. The levels of friction resistance the synthetic oil reaches, the regular may fall short of it. That may lead to wearing out for your engine’s moving parts.



Even if you carry out your own home viscosity test with the two types of oil, the synthetic will again prove its worth. How does viscosity have an effect in oil change for the engine? Dry starts should ring a bell. If you’ve had a dry start situation, you can attest it sucks!

With the regular, be sure you’ll get a lot of those during winter or when your car is stationary for long. It becomes super thick making it hard to flow to the engine.

The synthetic oil has a stable viscosity not affected by temperatures. Regardless of the temperatures changes, it retains its normal viscosity. That keeps your engine supplied with oil. A change from synthetic to regular will have you missing out on this.


As far as impurities go, the make-up components and compounds of the two oil types takes responsibility. The synthetic oil is man-made, therefore, only the best compounds and molecules are in place. That means the molecules that can result to contamination of the oil have no place in the composition.

The regular oil carries a downside when it comes to contamination. It has a tendency to breakdown easily. That leaves deposits, known as sludge, along the engine system.

The sludge harbors the proper movement of the engine parts reducing its performance level. For vehicles that travel over long distances, there sludge brings about clogging that’s a threat to your engine life.

Considerations During the Switch Over

There are a few precautionary measures you can put in place during your oil change phase. Since you are introducing a completely new type of oil to the engine, it is preferably better if you do it in gradual steps.

For the first oil change, switch from synthetic to semi-synthetic oil. That way, you’ll slowly give you engine a taste of conventional oil to an average extent. Now for your second oil change phase, you can introduce the convectional oil now. It is also important to change your oil filter too as you change your oil.

Your car model type is another consideration to be put in place. Most modern cars have an upper hand when it comes to switching in between oil. The old models may develop leakage problems. Therefore, if you own one, it is better if you consult your manufacturer before carrying out the oil change.


Switching your car oil without affecting its normal running is possible. The only factor that will take a shift is the performance output of your engine. However, it is preferably better if you don’t do too much change in between the two oil types.

If it is not necessary to switch to regular oil, it’s better off to keep going with the synthetic. It has a lot to of benefits to reap from compared to the latter. Nonetheless, you may prefer a move to regular due to economic factors, which is very much okay.

There’s however a better alternative to that. The semi-synthetic oil will help you kill two birds with one stone. It is not only a cheaper option, but also gives you the benefits of both oil types without picking one.

About Chris Lewis.

Chris Lewis is a passionate individual with a deep affinity for the world of automobiles. From a tender age, his fascination with cars was nurtured by his father, a seasoned mechanic based in the vibrant city of San Francisco. Growing up under the watchful guidance of his skilled father, Chris developed an early aptitude for all things automotive.

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