Is Amsoil Full Synthetic [Explained A-Z]

Synthetic oils are becoming popular day by day in both older and modern engines. Amsoil is one of the top oil manufacturers in the world. So, you may be wondering – is Amsoil full synthetic?

The answer is that Amsoil oil isn’t fully synthetic but rather 100% synthetic. What’s the difference between the two of them? Keep on reading to find out all about it.

You’ll also learn about the different types of base oils used to make the final motor oil you use in your engine and why synthetic oil is better than conventional oil. So, let’s dive in!

is amsoil full synthetic

Is Amsoil Full Synthetic? Answered A-Z

Amsoil is a very popular brand of motor oils and they make different types of oils. The majority of oils made by Amsoil are 100% synthetic in most cases with only some minor exceptions. For example, the oils that belong in the Signature series of Amsoil are 100% synthetic oil.

amsoil 100% synthetic oil

You can also look at the label of the oil bottle to make sure if the oil you’re selecting is synthetic or not. If the label says 100% synthetic oil, then you can rest assured that you’re getting a synthetic oil of the highest quality.

It’s important to keep in mind that 100% synthetic oil is superior to full synthetic oil as it contains a better use oil. You need to know about these things in detail before I share the list of Amsoil oils that are synthetic.

What Is A Full Synthetic And 100% Synthetic Oil?

Before diving deep into which Amsoil oils are synthetic and what makes them special, you need a clear idea of what full synthetic oils are. You’ll learn all about it in this section.

You’d be surprised to know that the terms fully synthetic oil and 100% synthetic oil don’t mean the same thing according to some people. Even though they sound the same on the surface, there’s a lot of difference between them in terms of the base oils used. Let’s break that down.

I’ll talk about what makes the two types of oils different in a moment. Before that, you need to understand a key concept. No matter what type of oil is in question, two main things make it up – base oils and additives.

Regardless of whether you’re dealing with synthetic oil, semi-synthetic oil, or conventional oil, all of them will have these two components. And the biggest difference between fully synthetic oils and 100% oils lies in the base oils.

Fully synthetic oil is made from Group III base oils. Even though the base oil is considered to be synthetic, a lot of people argue against it. The intense manufacturing process used to make this oil gives them the reputation that they are simply highly modified conventional oils.

But when it comes to Group IV base oils, they are known to be truly synthetic. Starting from the manufacturing process to the composition, they’re known to be synthetic oils from head to toe.

When someone refers to 100% synthetic oil, they are usually talking about oils that are made from Group IV base oils. This group of base oils is also called Polyalphaolefin (PAO) base oils.

What Are The Amsoil 100% Synthetic Oils?

Amsoil makes 100% synthetic oils instead of full synthetic oils. Now, you know that it means that they use Group IV base oils and not Group III base oils. So, let’s look at some of the famous Amsoil 100% synthetic oils.

01. Amsoil Signature Series 100% Synthetic Motor Oil

The most popular line of oils made by Amsoil for gasoline engines is the signature series. You can find this oil in many variants including OW20, 5W20, 0W30, 5W30, 10W30, 0W40, and 5W50 viscosities.

amsoil 100% synthetic oil signature series

There’s a misconception that using Amsoil oils can breach the warranty of your vehicle. But there’s no truth to that. You can expect to use it for about 25,000 miles or 700 hours – whichever comes first. Then, you’d need an oil change.

02. European Motor Oil

Just like the oils for the North American market, the Amsoil oils in Europe are also 100% synthetic. The popular variants in such oils are 5W30LS, 5W40MS, 5W40FS, 0W40FS, 0W20LS, and many more.

These oils are generally made for use in gasoline, diesel, and hybrid. The base oils are 100% synthetic along with some premium additives. You can expect the engine to be stable and get excellent performance from it.

03. Other Amsoil Oils

As I mentioned previously, the majority of Amsoil oils are 100% synthetic. Now that I have talked about the popular choices, there’s no point listing the oils one by one. You can find a list of all the Amsoil oils in the market here.

There are only a few racing and break-in engine oils made by Amsoil that aren’t 100% synthetic. The rest of them are synthetic. Here are some popular categories of other 100% synthetic oils made by Amsoil:

  • High mileage oil.
  • Racing oil.
  • High zinc oil.
  • Hybrid oil.
  • Diesel engine oil.
  • 2-stroke oil.

The list goes on and on. Hopefully, you get the idea. You may be worried about whether Amsoil is a reliable brand. It’s natural to wonder if Amsoil oil is worth it. Honestly, the answer is a 100% yes.

The oils made by Amsoil are 100% synthetic and that goes to show that they only use the group IV superior base oil. Along with their high-quality and compatible additives, selecting Amsoil will be a good choice for you. Stay tuned to learn more about synthetic oils.

Are Group III Base Oils Synthetic Or Not?

Just because a group of people think that the manufacturing process of group III oils doesn’t make them qualified to be a synthetic oil, you don’t have to believe it. It’s better to find out the truth on your own.

Luckily, there’s a blast from the past that will help you identify whether Group III oils can be labeled as synthetic or not. There was a lawsuit between Mobil and Castrol regarding this issue.

Mobil made a case against Castrol as they were using Group III base oils and marketing the oils as a “Synthetic oil”. The result is that Castrol eventually won and Group III oils were identified as synthetic.

So, an oil can be labeled and marketed as 100% or fully synthetic oil if it has base oil from Group III, IV, or V. Now, the composition of the oils can vary depending on the manufacturer.

It could have 80% Group III oil along with 20% Group IV oil and vice-versa. The main thing is that all the base oils have to be used from Group III, IV, or V. As long as oil manufacturers follow those rules, they can sell the oils as fully synthetic oils or 100% synthetic oils without any issue.

Are Group III, IV, and V Synthetic Base Oils The Same?

If these oils were the same, they would belong in the same group. But that’s not the case. And when you’re done reading this section, you’ll understand the difference between each of the oil groups.

I’ll talk about the properties of the different base oil groups individually. But before that, you should have a general idea. As you move from Group I to Group IV, the oils will get more and more refined.

It’s a good thing as they will be more efficient. But do you remember the first part of our discussion? I told you that two main components go into making an oil – and that’s additives. They’re equally important in determining the quality of the oil.

In general, Group IV oils will always be better than Group III, II, and I oils because it is more refined. But due to additives, that can change. A Group III oil with amazing additives can be better than a Group IV oil with low-quality additives. They’re a big game changer. Always keep that in mind.

With that said, let’s talk about the key differences between each of the different base oil groups.

01. Group I Base Oil Properties

The raw material used to make motor oil is crude oil. When the oil goes through very little refinements, it’s placed in the Group I base oil category. There are different hydrocarbons in this type of oil. It’s very unlikely to use this type of oil for automobiles.

02. Group II Base Oil Properties

This type of oil is a little bit more refined and is normally used in mineral-based motor oils. So, its main use is in making conventional oil. When it comes to factors like wear prevention and oxidation inhibition, they fare quite well. But they don’t have a good pour point.

03. Group III Base Oil Properties

These types of oils are further refined so much so that they go into making synthetic oils. They have a much better molecular uniformity compared to Group II oils and that can be easily observed in their performance. 

04. Group IV Base Oil Properties

The highest grade of synthetic oils is made from this type of base oil. Group IV base oils offer improved performance as they are made from Polyalphaolefins or 

PAO. The uniformity and stability of this type of oil is unmatched by all others.

05. Group V Base Oil Properties

This is a different type of chemically engineered oil that doesn’t belong in any of the other groups. Esters and silicone are some notable examples of the type of oils that belong in this group. 

What Is The Composition Of Synthetic Blend Oils?

Because of how well-defined the rules on synthetic oils are, you may think the same goes for synthetic blend oils. But that’s not true at all. There’s no clarity in terms of the composition of a synthetic blend oil.

As long as synthetic base oil is used in any quantity, an oil can be marketed as a synthetic blend. For example, even if an oil uses 1% Group III, IV, or V oil, and 99% Group I or II oil, it’s a synthetic blend.

The reverse of that is also true. If an oil uses 99% synthetic oil and 1% conventional oil, it will be a synthetic blend. So, there’s a lot of grey area to deal with in this particular category of oil.

So, it’s natural that you’d be a little confused when picking a synthetic blend.  Even though manufacturers don’t have to disclose the amount of base oils used, there’s a trick you can use to see if the oil is of good quality.

Look at the Viscosity Index (VI) of the oil. If the VI of the oil is on the higher side, there’s a good chance that it contains more synthetic oil rather than conventional oil. So, you can pick such an oil.

Another thing you can look at is the pour point of the oil. It is an indication of the lowest possible temperature at which the oil can flow. The lower the number, the more synthetic oil will be present in that oil. These are some hefty tricks you can apply if you want to get a high-quality synthetic blend.

What Are Some Advantages Of Using Synthetic Oil?

There’s no doubt that synthetic oils are better than conventional oils. But where exactly does the difference lie? I’ve listed 5 main benefits that you can expect to enjoy when you synthetic oil. Let’s take a look at them.

i) Improved Performance In Cooler Temperatures

The base oils that go into making conventional oils aren’t suited to perform well in colder climates. As the temperature goes down, the oil starts to get thicker, and it results in reduced engine protection.

cold weather

Compared to that, synthetic oils remain relatively fluid even in cold temperatures. Unlike conventional oils, they don’t have any waxes that thicken due to cold temperatures. So, you’ll get a much better performance from synthetic oils during the cold.

ii) Improved Performance In Warmer Temperatures

The superiority of synthetics isn’t only limited to cold temperatures. Even in extremely high temperatures, they’ll give better output than conventional oils. This is even more important than performance in cold weather as engines often get hot.

The molecules that are formed in conventional oils aren’t stable enough to withstand extreme heat. They vaporize when the temperature inside the engine gets too hot.

A common issue that is caused by using conventional oil is called turbo cooking. Turbos spin really fast and get hot at the same time. When the oil is left in the turbo and the engine is shut down, it cooks inside the turbo. It leaves a lot of unwanted deposits and this is called turbo cooking.

An engine oil of high quality is needed to prevent that from happening. That’s exactly where synthetic oils come into play. They’re much more resistant to high heat. There are a lot of car manufacturers that require the oils used in their engines to pass the turbo cooking test.

iii) Better Engine Protection

Synthetic oils provide better overall engine protection compared to conventional oils in both hot and low temperatures. Protecting the engine from wear and tear is without a doubt the most important function of an engine oil.

better engine protection

The fluid film produced by synthetic oils is more strong and stable compared to the conventional ones. So, the metal components rub against each other less frequently and the engine gets greater protection.

iv) Lower Oil Consumption

It shouldn’t come off as a surprise if you think about it but conventional oil gets depleted a lot quicker than synthetics. The reason behind this is that regular motor oils vaporize when the engine gets too hot. And the engine gets hot often.

In contrast, synthetic oils remain relatively much more stable during extreme temperatures. They don’t break down as easily and also offer greater protection to the engine at the same time.

The high volatility of conventional oil isn’t ideal for making it last long. Moreover, the low protection offered to engines can also lead to leaking gaskets, seals, and damaged bearings. All these things in turn will also lead to more oil consumption. That’s why synthetic oil is a much better choice in this matter.

v) Better Fuel Economy

In cold temperatures, conventional oil gets thick. Not only does it lead to reduced engine protection, it also forces the engine to work harder. So, more fuel is lost in the process.

In comparison, synthetic oils flow much more freely even at cold temperatures. So, the engine doesn’t have to waste any more fuel. So, you can expect a much better fuel economy if you use synthetic oils.

What Are Oil Change Intervals When Using Synthetic Oil?

You’ve already learned that using synthetic oil will lead to less frequent oil changes compared to regular motor oil. But that still doesn’t make it clear how often you’d have to change the synthetic oil.

Unfortunately, there’s no clear answer to that. Base oils are only a part of the equation as additives also play an important role in the formulation of the oil. While most oils can last for 8.000-10,000 miles, there are also oil brands that claim you can use them for as high as 25,000 miles.

Oil change frequencies also depend on driving conditions and habits. Things like excessive idling, and ploughing will surely have an impact on the usable lifetime of an oil. It’s a good idea to follow the recommendation of your car manufacturer or the label on the oil bottle.

Is It Okay To Mix Synthetic Oil With Conventional Oil?

It’s not the end of the world if you decide to mix synthetic and conventional oils together. Essentially, that’s what synthetic blends are. But keep in mind that you’ll be minimizing the performance you can expect from a pure synthetic oil if you do that.

mixing oils

Also, keep in mind that the types of oil also contain different additives. So, they won’t be compatible with one another. It’s okay to mix the two types of oils in emergency situations like when you’re low on oil and your only option is to mix the two oils.

In such cases, you can relax and just combine them. Relax, your engine won’t explode if you do that. Just make sure that you drain the oil after the emergency is over and only use the full synthetic oil.

Does Synthetic Oil Cause Any Issue In Old Cars?

The fact that synthetic oil can damage older engines is nothing but a myth based on modern oils. However, there is a little truth behind this common misconception that started many years ago.

clder cars

When synthetic oils first came to the scene, they weren’t as effective as they are now. When they were used in the engines, a lot went wrong with them. To be honest, those synthetic oils were to blame for these issues.

But technology has come a long way and oil manufacturers have mastered the art of making synthetic oils. That’s why it’s safe to say that modern-day synthetic oils won’t have any negative effect on an engine. In fact, it will help the older engines run even better and protect them from wearing out.


Which oils are more refined – conventional or synthetic?

Synthetic oils are a lot more refined than conventional oils even though they are made from crude oil. In contrast to food, refining oils make them better and you can expect a better performance from the synthetic oils.

Are all base oils the same?

Broadly speaking, base oils have been divided into five groups. Groups I and II are conventional base oils whereas Groups III, IV, and V are synthetic base oils.

How can you switch from conventional to synthetic oil?

You won’t have to do anything special to switch from regular motor oil to a synthetic one. Simply, drain the old oil from your engine and replace it with the new synthetic oil.

Are synthetic oils better than conventional oils?

Generally speaking, synthetic oils are better than conventional oils as they have better base oils. But additives are equally important and a high-quality conventional oil can outperform a synthetic oil with poor additives.

Is there any disadvantage to using synthetic oil?

In terms of performance, synthetic oils are much better. But they are also much more expensive and that’s the main downside to them. However, if you look at it as an investment in the long term, it’s well worth the price.


Is Amsoil a full synthetic oil? Now, you know that Amsoil has oils in many different variants and 100% synthetic oils are a very big part of that range. Most of the oils produced by Amsoil are 100% synthetic.

Hopefully, you also understand the difference between fully synthetic and 100% synthetic oils now and why the latter is better. Drop a comment below if anything is confusing to you or if you have any questions.

About John M

John contributed as a technical head at an automobile company just 2 years after his post-graduation in Automobile Engineering. He loves to lead a free life, so he left his job & started blogging. Now, he does research on every automotive problem, part & product and seeks a better solution & best products & shares his findings with his readers to help them as well as to minimize their struggle.

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