What Are The Disadvantages Of Synthetic Oil? 

Can you tell me a few disadvantages of synthetic oil? No? Don’t worry, we are here to help you. Before knowing the disadvantages, let’s know about what is synthetic oil made from first. Synthetic oil is a man-made lubricant with scientifically designed molecules. Scientists made this molecule by breaking it down and then rebuilding the petroleum molecules. Therefore, when you observe a drop of synthetic oil under a microscope, you will see millions of molecules all nearly the same size and structure. On the other hand, a drop of conventional oil under a microscope shows millions of molecules all with different shapes, sizes, and structures. Let’s take a look at the disadvantages of synthetic oil. 

What Are The Disadvantages Of Synthetic Oil? 

To know the disadvantages of synthetic oil take a look at the list given below, then we will see them in detail. 

  1. More expensive 
  2. It Restricts The Breaking In Of Newer Vehicles 
  3. It Can Harm Old Vehicle Models 
  4. Does Not Lead The Engine 
  5. It Does Not Work With Rotary Engines 
  6. Problems With The Racecar 
  7. Improper Disposal Of Synthetic Oil 
  8. Health Issues 
  9. Pollution 

9 Disadvantages Of Synthetic Oil 

Here is a detailed explanation of the all disadvantages of synthetic oil and it makes you more aware of synthetic oil.

  1. More Expensive 

When you compare synthetic oil vs regular oil, then you will find the price of synthetic oil is more than conventional oil because of its higher quality. You also need to take into consideration its high production cost. If you are facing financial problems then you can switch to conventional oil.

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  1. It Restricts The Breaking In Of Newer Vehicles 

Is synthetic oil worth it for new cars? No, as synthetic oil is not recommended to brand new vehicles or the newer ones. It is because newer cars will need a certain level of friction to break in their moving parts, they usually need a lot of friction that can be supplied by using petroleum-based oil. This is one of the disadvantages of using synthetic oil for new vehicles.

  1. It Can Harm Old Vehicle Models 

One of the common disadvantages of semi synthetic oil is it can harm your old vehicle models. This is because the synthetic oil cleans the sludge out and the old vehicles generally use deposits that act as the seating in their oil system. While synthetic oil is just doing what it is supposed to, which is cleaning out the deposits.

  1. Does Not Lead The Engine 

Synthetic oil does not hold the lead in the suspension of motor oil. So, in the older car engines, the oil needs to lead for gasoline to run the engines which are not possible by this oil.

  1. It Does Not Work With Rotary Engines 

Why does synthetic oil not work with rotary engines? It is because synthetic oil sometimes causes rubber seals to swell after years of immersion in mineral oil. Also, because synthetic tend to be high-detergent by their nature, so changing deposits to be scoured away, leading to higher oil.

  1. Problems With The Racecar 

Synthetic oil causes problems to race cars because of the roller lifters of the racecar. And because of less friction with the use of synthetic oil the rollers of race cars slide instead of being turning as designed. So, it is also a huge flaw for synthetic oil.

  1. Improper Disposal Of Synthetic Oil 

Improper disposal of synthetic oil is one of the biggest issues and also biggest contributor in the environment pollution. Therefore, it is very essential to learn about the disposal of used oil before changing to synthetic oil. Disposal of used synthetic oil is quite complicated but there are many methods to dispose of it.

  1. Health Issues 

How can synthetic oil create health issues? So, when people dump used synthetic oil improperly, it can cause many severe health issues for those who use water from those areas. According to a study, 40% of the pollution in many countries occurs from improper disposal of synthetic oil and solid waste.

  1. Pollution 

One of the biggest downsides of used motor synthetic oil is environmental pollutants. Because when oil is used, most people do not dispose of it properly. Ultimately, it ends up in water resources and teams including groundwater just because it is not dumped properly. After some time, it is very difficult to remove the oil from these resources.

Advantages Of Synthetic Oil 

The advantages of synthetic oil are, 

  • Uniform composition 
  • Fewer impurities 
  • Higher flash point 
  • Oxidation stability 
  • Longer survive life 
  • Higher viscosity index 
  • Biodegradability 
  • Better energy efficiency 

Everything has its disadvantages on Disadvantagess you will get to know more.


When Should You Not Use Synthetic Oil?

This being said, however, it is still not recommended to use synthetic oil in engines that have experienced significant actions – specifically, those that have reached around 75,000 miles on the odometer.

Why You Shouldn’t Use Full Synthetic Oil?

This is because many synthetic oils contain esters, which are organic compounds mixed with alcohol. This particular combination can be extremely rough on seals within the engine, which can cause the seals to wear down and begin to leak or burn oil.

Can You Go Back To Regular Oil After Synthetic?

Answer. Synthetic oils typically provide better protection than conventional oils, but switching back and forth between full synthetic and conventional oil will not damage the engine.

Does Synthetic Oil Reduce Mileage?

A synthetic oil is exactly that, it has all of the properties of a mineral oil, but manufactured to reach new levels in flow, viscosity, efficiency, performance and last but not least, mileage. It effectively does the same thing as a blend or mineral oil, but better in every way.

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What Are The Pros And Cons Of Synthetic Oil?

It’s the main disadvantage of this type of oils. They are a couple of times more expensive than the petroleum-based motor oils. However, they take better care of the engine, increases its lifespan, and improves fuel economy. So, you’ll eventually find them cost-efficient.

Why Do We Not Use Synthetic Fuel?

Synthetic fuels are less efficient still, with the estimate being about 4 times worse than batteries and very little improvement by 2050. In other words, powering the current car fleet with synthetic fuels instead of batteries will require four times as much electricity generation, which seems completely impractical.


While going through the article you have come to know about the advantages and disadvantages of synthetic oil in detail. There are several types of synthetic oil including, synthetic blend oil, full synthetic oil, and semi-synthetic oil. One thing about synthetic oil you must know is how long does synthetic oil last. So, synthetic oil lasts until it covers a distance of 7,500 to 15,000 miles. Now, you have understood everything about the disadvantages of synthetic oil

Can synthetic oil be bad for your engine

What are the disadvantages of synthetic oil?