Semi-synthetic Oil vs Fully Synthetic Oil – Which Engine Oil is Best?

It’s best to keep in mind that keeping your engine well lubricated is essential since it helps to keep your engine running smoothly. And your engine oil is what does the job. One thing for sure is that no car can function without engine oil.

When it is time to change your engine oil there are several factors to keep into consideration. First you’ll have to understand the viscosity of the engine oil, the brand and grade of the engine oil and whether the oil is semi-synthetic or fully synthetic.

At this point you may be confused but let me give you a brief break down. Semi-synthetic oils are known to be a mixture of 25% synthetic and 75% mineral oil, while full synthetic oils are considered to be 100% synthetic oil and should not be mix with other oils. In terms of cost, high-performance and ability to resistance, we strongly believe that the fully synthetic oil is better than the semi-synthetic oil.

In this article, we have provided you with everything you need to know about full synthetic oil and semi-synthetic oil, including what they are and which oil is best to use.

Difference Between Semi-Synthetic Engine Oil VS Fully Synthetic

Semi-synthetic Oil vs Fully Synthetic Oil

In order to lubricate the different parts of your engine, it’s best to know the different types of oils since some oils tend to reduce friction and allow loss of power within your vehicle. The thing is that the substance of oils actualky varies base on the nature of the oil, such as semi-synthetic oil or fully synthetic oil.

Full synthetic oil comes from the same crude oil like mineral oil, but how these oils are produced is completely different and even have significant differences in how they actually performs. Fully oil is refined, distilled and purified in a way that allows individual molecules within the oil to be tailored to meet the demands of modern car engines.

Full synthetic oil is known to degrade at a slower rate when compared to mineral oil so it will perform at a superb rate for a long time. Fully synthetic oils are often used in newer vehicle that comes equipped with turbocharged engines as they are known to operate at much higher temperatures than standard engines.

While on the other hand, semi-synthetic is widely known to be a mixture of fully synthetic oil and conventional mineral oil. It’s best to keep in mind that semi-synthetic oil is capable of achieving higher levels of performance than mineral oil by itself.

Apart from that, semi-synthetic oils are considered to be on the more affordable side which is great for those on a tight budget, while still providing you with some of the benefits of full synthetic oil.

Read More: Is Synthetic Oil Flammable

Semi-synthetic Oil vs Fully Synthetic Oil – Which is the Best?

We strongly believe that full synthetic oil is the more efficient oil when compared to semi-synthetic even though full synthetic oil is on the more expensive side. The thing is that the molecule size the full synthetic oil is pretty much the same. As you can see, this oil will definitely lubricate the engine parts which will help to reduce friction and minimize the loss if power.

With that said, fully synthetic oil is designed base on quality and it is not mixed with any other oils. Semi-synthetic on the hand is said to have a ranges of molecules as it is based on two types of oil including mineral oil and synthetic oil. It is unable to contribute to friction and minimize unnecessary loss of power than fully synthetic oil.

But semi-synthetic oil is much cheaper when compared to fully synthetic oil which is great for those on a tight budget yet looking for a oil that’s high quality.

Can You Use Semi-synthetic Oil Instead of Fully Synthetic Oil?

We think the best thing to do is use the oil that is recommended by your manufacturer since it is always the safest option.

If it’s a case where you decide to use semi-synthetic oil instead of fully synthetic oil then it is unlikely to cause any serious issues to your vehicle right away. However, it’s best to keep in mind that your engine will not get the same protection as it would us ing fully synthetic oil and it may even result in reduce engine performance as well. So, if fully synthetic oil is recommended, then it is best to use it.

Also Read: P06DD Engine Oil

FAQs – Frequently Asked Questions

Q. Is semi-synthetic oil good?

Yes, due to the fact that semi-synthetic oil is much better than mineral oil but it is not better than fully synthetic oil. If you are on a tight budget, yet looking for a decent quality oil, then you can definitely go with semi-synthetic oil.

Q. Does semi-synthetic oil last longer?

Yes it does, it tend to last for roughly 5,000 miles. However, the temperature might play a role in affecting the viscosity of the semi-synthetic oil. We think it is best to change the oil every 5,000 miles along with your oil filter.


As you can see, both oils are great to use just that the fully synthetic oil is considered to be the better option, but you still can’t go wrong with using a semi-synthetic oil. However, befo re using any oil, we highly suggest that you check your owner’s manual to see which oil is recommended by your car’s manufacturer since that would be the best option for yoi r car.