Top 5 100% Synthetic Oil Brands [You Can Trust]

Synthetic oil has a ton of benefits. This type of motor oil will maximize fuel efficiency and ultimate engine performance by shielding your engine from wear & tear. But not every brand delivers 100% Synthetic oil. Instead of offering 100% synthetic oil, they provide full synthetic oil. And there is a difference between these oil types.

Fortunately, we broke down the subtle difference between the 100% synthetic and full synthetic oil. And lastly, I’ll recommend the top 5 100% synthetic oil brands. So, keep reading till the end.

Table of Contents

• Is The Oil Really 100% Synthetic Oil As Labeled or Marketed?
• Is There A Difference Between 100% Synthetic Oil Vs Fully Synthetic Oil?
• Top 5 100% Synthetic Oil Brands You Can Trust [Honest Opinion]
• What About Amsoil Oil and Is It Full Synthetic?
• Which Is Better – Castrol Or Royal Purple?
• Is Synthetic Oil Better For Diesel Engines?
• Are Synthetic Oils High In Zinc?
• Conclusion

Is The Oil Really 100% Synthetic Oil As Labeled or Marketed?

Honestly, no oils in the market, whether from Mobil or Castrol, use a 100% synthetic base. It means the oil marketed as 100% synthetic is actually not 100% synthetic. They use a 10-20% mineral oil base. However, some oil companies use 90% synthetic additives.

Generally, 100% synthetic is a fancy marketing term. If the label of the oil bottle says such, the oil should be 100% fully synthetic by regulation. If you see the words ‘100% Synthetic’ on a bottle, I bet every single oil drop in your bottle is a synthetically produced compound, mixed with fully synthetic additives.

If you take the term 100% synthetic oil at face value, you’ll know that there is no such oil in the market. That’s because synthetic oil doesn’t just drop out of thin air. The raw material of oil is crude oil and it’s only produced to make synthetic oil.

Once it goes through a required amount of refinement and passes certain purity tests, you get Group IV base oil. For an oil to claim that it’s 100% synthetic oil, it has to use this base oil. Then, it’s mixed with additives to deliver a great final product that can make your engine smooth like butter.

Is There A Difference Between 100% Synthetic Oil Vs Fully Synthetic Oil?

Yes, there is a difference between 100% synthetic oil and full synthetic oil. The 100% synthetic (API Type IV) oil is specially formulated with a synthetic base and synthetic additives. In other words, a 100% synthetic is a combination of synthetic base PAO/ Ester along with synthetic additives.

On the other hand, full synthetic oil is a highly refined petroleum base with synthetic additives. In other words, fully synthetic oil is a combination of 50% petroleum base and 50% synthetic additives.

Let’s break this down a little more so you can understand it more easily. All oils are made from two main things – the base oil and additives. These days, the base oils are largely divided into four groups. They are named Group I through  Group IV base oils.

The Group I base oils are the least refined ones. As you move to a higher group level, the oil gets more refined. So, Group II is slightly more refined, and Group IV base oil is the most refined.

So, which one is the most superior in terms of base oils? Remember this rule – base oil is the opposite of food. While food like oats and wheat are best when they’re not refined, it’s completely opposite when it comes to oils. The more refined the oil is, the better it is.

So, Group IV oils are the highest quality base oil you can ask for. As you move down, the quality gets lower and lower. Now, 100% synthetic oils are normally made from Group IV base oils. In contrast, fully synthetic oils are generally made from Group III base oils.

If it comes to 100% synthetic vs fully synthetic oil, you can expect the oil that’s made from Group IV base oil to be superior. So, 100% synthetic oil is the better choice. However, remember that it’s only one part of the equation.

Additives also have an equally important role here. This is where the brands differ from each other and have their own engineering in making the oils better. Therefore, the better oil between full synthetic vs 100 synthetic oil can also vary depending on the brand you choose.

You’ll learn about the differences in synthetic oil brands as you read this guide. Are you ready to know about the best fully synthetic oil and 100% synthetic oil brands? Let’s look into the top synthetic oil brands in detail.

Top 5 100% Synthetic Oil Brands You Can Trust [Honest Opinion]

There are many high performance motor oil brands that produce 100% synthetic oil. Based on my personal usage experience as well as what I have seen in my friend circle, let’s find out who makes the best synthetic oil.

01. Castrol

Castrol is the leading oil brand among synthetic engine oil brands that makes a huge name and fame by providing 100% synthetic and fully synthetic oil for vehicles. It reduces friction and prolongs the life of your car engine by lubricating the internal components.

For example, its Castrol Edge Performance Full Synthetic Motor Oil improves the oil film strength by 30%, reducing metal-to-metal contact. Indeed, you can go a long way (20000 miles) between oil changes without worries.

Therefore, this high-performance engine oil won’t get thickened under extreme temperature conditions. In other words, there is less risk of forming deposits & sludge in the engine compartment.

However, the following 2 synthetic oils from Castrol are highly popular and recommended because they can dramatically reduce friction and extend your car engine life.

• Castrol Edge Performance 5W-30 Advanced Full Synthetic Motor Oil
• Castrol GTX MAGNATEC 5W-30 Full Synthetic Motor Oil

02. Mobil 1

Mobil 1 is also a top-rated & reliable oil brand that offers high-quality synthetic oil. It offers pure synthetic oil to prevent sludge & deposits from forming in the engine compartments. When you make synthetic oil comparisons of different brands, Mobil 1 is likely to come out on the very top.

The precise balance of performance additives delivers outstanding engine protection at oil change intervals. Its superior thermal & oxidation stability works as a barrier to oil breakdown. It means this oil keeps the internal metal components of your engine well-lubricated and protects the engine.

Turns out, this engine oil also works well in cold weather. Indeed, this is one of the high-performance synthetic oils for Subaru. And definitely, you can consider the following most popular and TOP-Selling synthetic oil from Mobil 1 for your car engine’s safety and protection.

• Mobil 1 Extended Performance Full Synthetic Motor Oil 5W-30

03. Royal Purple

Royal Purple is one of the best synthetic oil brands in the world. This oil brand is well-known for its proprietary Synerlec additive technology. Due to this technology, oil from Royal Purple can prevent white sludge & lubrication.

If you’re looking for examples of synthetic oils that have been made with attention to detail, Royal Purple fits the description perfectly. Therefore, the patented anti-wear additive chemistry reduces the harmful effects.

Plus, the enhanced additive technology prevents metal contact to maximize engine life. So, if you are a Royal Purple user, we recommend you get the following synthetic oils from Royal Purple for your vehicle to increase fuel efficiency & engine performance.

• Royal Purple HPS 10W-40 High-Performance Street Motor Oil
• Royal Purple SAE 10W-30 High-Performance Synthetic Motor Oil

04. Pennzoil

Another great synthetic oil lubricant is Pennzoil. It’s the first motor oil brand that uses natural gas to produce pure synthetic oil. It utilizes patented gas-to-liquid PurePlus technology that converts natural gas to base oil.

Unlike conventional oils, Pennzoil Synthetic Motor Oil can handle severe driving conditions. It outperforms traditional oil in terms of low-temperature performance and volatility control.

Therefore, Pennzoil synthetic oil provides unsurpassed wear protection against friction. The oil from Pennzoil also delivers superior engine protection against sludge & deposit buildup. Indeed, Pennzoil is one of the best full synthetic oil brands for maximizing engine performance & fuel economy. And when you are planning to use oil from Pennzoil, then you can pick one from the following:

• Pennzoil Platinum Full Synthetic 5W-20 Motor Oil
• Pennzoil Ultra Platinum Full Synthetic 5W-30 Motor Oil

05. Shell Rotella

At the bottom of the list, we bring another reliable oil brand named Shell Rotella. It features Triple Protection Plus Technology. Shell Rotella is specially formulated with fully synthetic base oil. Indeed, the synthetic oil from this brand enhances engine performance by boosting fuel efficiency.

Turns out, Shell Rotella uses advanced additives in combination with synthetic base oil. In other words, this oil delivers superior protection against soot, dirt, and other contaminants. 

The advanced low-ash formulation helps control contaminants like dirt & ash, which maximizes engine fuel efficiency. If you make up your mind to get synthetic oil from Shell Rotella, go for: 

• Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil

What About Amsoil Oil and Is It Full Synthetic?

When it comes to top synthetic oil brands, it’s hard not to mention the name of Amsoil. Even though it didn’t make the top 5 list, it definitely deserves an honorable option. The line of synthetic oils that Amosil produces is also of the highest quality and may be the right choice depending on your engine.

Is amsoil full synthetic? That’s a question I get asked often and the answer is that it’s not. It’s even better. It’s 100% synthetic oil as it’s made from Group IV base oils. So, it can be also be oil worth considering if you want to look into Amsoil. I’ve used Amsoil for many years and that’s why I wanted to mention it.

In fact, I have a detailed guide on Amsoil synthetic oils that you’ll hopefully find useful. You’ll learn about the different viscosities in which you can find them. There’s also a detailed section explaining the difference between the four oil groups. Feel free to check it out if you want to know more about it.

Which Is Better – Castrol Or Royal Purple?

Castrol and Royal Purple are two of the biggest names when it comes to oil brands. And you may have your own favorite picked out already if you’ve used them before. But for those who haven’t used it, a lot of people wonder which one is the better of the two.

Truth be told, there’s not any noticeable difference in terms of the specifications of the oil. However, the price of Royal Purple is generally a little bit higher than Castrol.

So, if you want the budget-friendly option between the two, I’d say go for Castrol. But the difference isn’t too much and you should prioritize the requirements of the engine.

Choosing the winner from the Castrol Edge vs Royal Purple battle can be tough. If you’re unsure what to get, I’d recommend getting Castrol once, use it, and then, switch to Royal Purple. Then, compare which one works better for your car from your actual experience.

I have a more detailed guide in which I compare Castrol and Royal Purple oils with one another. You’ll learn about the different types of variants in each of those oils and pick the one you like better.

Is Synthetic Oil Better For Diesel Engines?

If all other things are the same, using synthetic oil is always better than using conventional mineral oils. It doesn’t even matter if it’s a diesel or a gasoline engine. That’s the real talk despite whatever else you hear.

Not all diesel engines even require synthetic oil. So, you’d be wasting a few extra bucks if you needlessly spend on synthetic oil when the engine clearly doesn’t need it.

But if you really don’t care about spending a little extra and want to use the best possible option for your engine, you can go with synthetic. You can get the following benefits from it:

• Better wear protection.
• Improved cold weather performance.
• Less formation of sludge in the engine.
• Reduced consumption of oil.
• Longer engine life in the long run.

However, keep in mind that the more important thing is to maintain the viscosity of the oil recommended by the manufacturer. Don’t use a different viscosity oil just for going synthetic.

If you can find a good synthetic option in the required viscosity for the engine, then you can definitely use it for a better performance. But if your engine doesn’t require it, not using it is also an equally viable option.

Well, to learn more about the benefits of using synthetic oil, you can go through the complete guide on is synthetic oil better for diesel engines.

Are Synthetic Oils High In Zinc?

There’s a long history of how Zinc was used in older cars. But it had a bad effect on the environment with too much carbon emissions. So, as the restrictions got tighter, the quantity of ZDDP in oils started to go lower and lower with time.

Regardless of whether you’re getting a synthetic or conventional oil, if you were to pick an oil at random, it would most likely be low in Zinc. However, if you specifically look for a Zinc synthetic oil, you’ll find it. Both Valvoline and Royal Purple provide such options.

If you want to know about specific high-zinc synthetic oils and the history of reducing ZDDP content in oil, I have a dedicated guide for you. Check out all you need to know about Zinc in synthetic oils and find out how you can use them.

Conclusion

100% synthetic and full synthetic oil is not the same. A full synthetic oil is less pricey than 100% synthetic oil. But the 100% synthetic boosts up fuel efficiency and engine performance.

Keep in mind; that no brands offer 100% synthetic oil. You can check out this article to explore the truth behind our saying- no oils are 100% synthetic. So, it’s better to test the oil and observe which synthetic oil performs the best. Fortunately, the five oil brands we recommend offer the best synthetic oil in the market.