10 Best Synthetic Motor Oils in 2021

Best Synthetic Motor Oil

The debate surrounding synthetic motor oils is a longstanding one. You’ll most probably come across a storm of opinions on their performance as opposed to conventional oils. Yet, one fact is clear- the benefits of synthetic motor oils are definitely visible if your vehicle is ready to carry them! 

Does the appeal of synthetic motor oils tempt you? If you find yourself nodding “yes” to this, you’re at a fortunate place. The array of these oils available today may puzzle you when it comes to picking the best. Especially when several of them seem to market themselves as superior! 

Below, you will find a carefully-curated list of 10 genuinely superior synthetic motor oils. These are the best in the game, so you can rest assured of their quality and performance. Read on. 

Remember to always follow your engine manufacturer’s recommended specifications for your engine oil before you buy one

Are you eager to learn more about the aspects of the best synthetic motor oils? Here’s a glance at the top picks from the list. 

Best Overall

Castrol 03057 GTX MAGNATEX

Castrol 03057 Gtx Magnatex 5W-30
  • Reduces engine wear
  • Affordable for the quality
  • Inserts a coat of protection

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Premium Choice

Liqui Moly 2041 Premium

Liqui Moly 2041 Premium 5W-40
  • Conserves energy
  • Fully synthetic 
  • Works both with gas and diesel 

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Budget Choice

Valvoline High Mileage with Maxlife

Valvoline High Mileage With Maxlife
  • Ideal for buyers on a lower budget 
  • Anti-Wear Additives
  • Prevents Sludge

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The 10 Best Synthetic Motor Oils in 2021

1. Liqui Moly 2041 Premium Synthetic Motor Oil

Liqui Moly 2041 Premium Synthetic Motor Oil

The Liqui Moly 2041 Premium Synthetic Motor Oil has “premium” right in its name. It hails from Germany, with top-tier production standards. It is a synthetic staple oil for European cars, that’s for sure.

It provides excellent security against engine wear. It offers a long life of service for your engine thanks to its quick delivery of oil at low temperatures. In addition to this, it flaunts incredibly high lubrication dependability at any temperature. This characteristic results in brilliant engine purity or cleanliness.

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The Liqui Moly 2041 Premium Synthetic Motor Oil holds several approvals, including ACEA A3 and B4, API CF, and SN. Vehicles that must comply with Porsche A40, VW 505 00, BMW Longlife-98, and MB 229.3 specifications are the recommended synthetic oil subjects.

A glaring advantage that you cannot overlook is that it works with both diesel and gasoline engines.

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Pros

  • Functions well with gas as well as diesel
  • Curated for rapid delivery of oil at low temperatures
  • High lubrication at all temperatures
  • Protects against wear
  • It keeps the engine pure and clean

Cons

  • Prone to spillage when opening

2. Castrol 03057 GTX MAGNATEX Full Synthetic Motor Oil

Castrol 03057 Gtx Magnatex Full Synthetic Motor Oil

Are you looking for an oil that will radically bring down the level of wear your engine suffers? The Castrol GTX MGNATEC is your answer. It gives its word that your engine parts will function up to 4x smoother than before.

This motor oil’s unique characteristic is its formulation- comprising intelligent molecules that latch onto the engine. This persists regardless of the driving conditions, even when your vehicle’s engine is shut down.

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The Castrol GTX MAGNATEC protects your engine in an unmatched manner, mainly because 75% of engine fraying happens during warming up. It saves up valuably since there is no need for extensive recirculation and lubrication after starting the engine.

You can buy the Castrol GTX MAGNATEC in 10W-30, 5W-30, 5W-20, and 0W-20 variants. The viscosity drives the performance claims, but at the very least, it meets API SN and ILSAC GF-5 standards.

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Pros

  • Reduces engine wear
  • It turns vital engine parts smoother
  • Inserts a coat of protection over the engine
  • Satisfies numerous standards

Cons

  • The container may leak easily
  • Viscosity options are limited

RELATED: What Does SAE Stand for in Motor Oil?


3. Valvoline High Mileage SAE Synthetic Blend Motor Oil

Valvoline High Mileage Sae Synthetic Blend Motor Oil

Valvoline is quite a well-known brand, with a practical and highly functional range of motor oils. The Valvoline High Mileage Synthetic Blend Motor Oil comes with seal conditioners that invigorate engine seals that are aging. They stop and prevent oil leaks, too- a common occurrence in high mileage engines.

In addition to this, the Valvoline High Mileage Synthetic Blend Motor Oil serves your engine with added protection against wear and contamination. The detergents in this oil keep your engine clean since they bond with and remove deposits and sludge. There are antioxidants in it, too, preventing oil breakdown.

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The additives in this oil against wear can persist in the harshest conditions as per friction and temperature. Most viscosity grades of the Valvoline High Mileage Synthetic Blend Motor Oil exceed or at least meet the standards of GM dexos1 Gen 2.

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Pros

  • It contains seal conditioners that refresh old engine seals
  • Offers extra armor against wear
  • Averts engine sludge

Cons

  • The cap of the jug is not well-fitting and secure

RELATED: 12 Common Engine Oil Myths


4. Castrol 03084C Edge Advanced Full Synthetic Motor Oil

Castrol 03084C Edge Advanced Full Synthetic Motor Oil

Are you on the hunt for maximum functioning and security for your vehicle? The Castrol 03084C Edge Advanced Full Synthetic Motor Oil with Fluid Titanium Technology is your best bet.

The technology claims to have a transformational effect on the oil’s structure under pressure, keeping metals away from each other. It dramatically reduces friction that can steal away horsepower.  

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The Castrol Edge increases the strength of oil film by about 30%. When you compare it to the industry typicals, this motor oil is 10x stronger versus heat and 6x stringer versus wear. Your fuel efficiency and the economy will benefit from the 0W grades.

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Pros

  • Offers impressive strength under pressure
  • It brings down metal-to-metal contact
  • Meets several standards

Cons

  • May turn dark faster than its rivals

5. Valvoline Advanced Full Synthetic Motor Oil

Valvoline Advanced Full Synthetic Motor Oil

Valvoline has another spot on this list, owing to its sheer reliability and cost-effective nature. The Valvoline Advanced Full Synthetic Motor Oil from the SynPower range guarantees cleanliness and protection against sludge for your engine.

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Your engine will remain protected under high heat or cold under extreme driving conditions too. The oil flow is quicker when starting the engine. The Valvoline Advanced Full Synthetic Motor Oil has a specific design to fight engine stress caused by heat, wear, and deposits.

It contains superior anti-wear additives that remain in the oil for a long duration. The viscosity grades of 5W-30, 5W-20, and 0W-20 meet GM dexos1 Gen 2 requirements.

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Pros

  • Protects the engine against varnish and sludge
  • Regulated fuel efficiency
  • Exceeds industry standards for most American vehicles

Cons

  • The jug is not ergonomic to use while pouring
  • Oil may contain conventional mixes and blends

6. Royal Purple 51530 High-Performance Motor Oil 5W-30 (5QT) 

Royal Purple 51530 High-Performance Motor Oil

The Royal Purple motor oil is one of the best options you can choose for your vehicle. This is because it is a widely trusted name among automobile aficionados. Current technology use and innovative practices are just a few reasons why this synthetic oil is a good option. 

The additive technology in this motor oil provides an excellent fuel economy and prevents any excess damage caused to the vehicle’s exhaust system. It also reduces metal-to-metal contact in the vehicle and makes it more efficient. 

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  • Better wear protection
  • Increased protection against LSPI
  • Increased fuel efficiency
  • Better protection for vehicle exhaust...

Another essential feature of this oil is that it reduces sludge caused by high amounts of gasoline-ethanol blends. This is because of the oil’s additive technology, and you must consider buying it if you use fuel that has ethanol. 

It has high corrosion-resistant properties, and it also protects against LSPI. The cost of this fuel might throw most people off. However, the properties and the efficiency of it make it worth the consideration. 

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Pros:

  • Improved protection 
  • Better fuel efficiency 
  • Enhanced ethanol compatibility 
  • ILSAC GF-5 and dexos1 requirements met
  • Catalytic emission system protected

Cons: 

  • It can be considered expensive 
  • Not many options for viscosity

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

Rotella Shell Rotella T6 Full Synthetic 5W-40

Shell is a well-known brand in the motor oil industry. However, this synthetic motor oil is one of our top choices because of its wide array of features. Studies conducted on this product prove that it is set to improve your vehicle’s fuel economy by no less than 1.5%.

The unique additive formula of this synthetic motor oil protects your engine and the rest of your vehicle’s components. This increases its lifespan as it also protects against dust, soot, and other elements that could contaminate your engine. 

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This motor oil is extremely stable and prevents any viscosity loss too. It helps maintain the oil pressure adequately and continuously enhances the performance of the machine. It works excellent with diesel automobiles, including tractors and trailers.  

The product has all the necessary specifications and certifications that make it an excellent choice for any vehicle. Be it cars or pick-up trucks. Here are a few mentioned below. 

API: Caterpillar ECF-2/ECF-3; Allison TES 439; Cummins CES 20086, 20081; CK-4, CJ-4, CI-4 PLUS, CI-4, CH-4; ACEA E9; MB-Approval 228.31; JASO MA/MA2; MAN M3575; Ford WSS-M2C171-F1; JASO DH-2; Detroit Fluid Specification (DFS) 93K222, 93K218; and Volvo VDS-4.5, 4.

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Pros: 

  • Premier additive formula 
  • Increased fuel efficiency 
  • Protection against dirt and contaminants 
  • Shear stability 
  • People’s favorite 

Cons: 

  • Not very inclusive 

8. Mobil 1 (120766) Extended Performance 5W-30 Motor Oil – 5 Quart

Mobil 1 (120766) Extended Performance

Another top contender is the Mobil 1 synthetic motor oil. This is a fantastic choice for automobile enthusiasts because of its innovative additive formula. This unique formula elongates the engine’s life and makes it more fuel-efficient. 

This is because one of the best qualities of this motor oil is that it maintains oil viscosity and protects the engine’s vital components against sludge, dirt, etc. It has remarkable lubrication and reduces physical wear and tear in the machine. 

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This oil is especially great for people living in colder regions. The additive formula of this oil makes it very easy to restart your engine in cold temperatures. Its unique formula prevents the possibility of oil breakdowns too. 

It is an affordable choice for most people. Motor oil is highly compatible with a wide range of automobiles. However, it is advised that you cross-check the compatibility once before using it.

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Pros: 

  • Trusted brand 
  • Fuel efficiency 
  • Temperature protection 
  • Dirt protection 
  • Oil breakdown is reduced 

Cons:

  • Chances of engine becoming noisier 
  • Price variation observed from place to place

9. Pennzoil Platinum Full Synthetic Motor Oil 5W-30 – 5 Quart

Pennzoil Platinum Full Synthetic Motor Oil

This Pennzoil motor oil was created with the help of a premier gas-to-oil technology. This process is credited to converting pure natural gas to synthetic base oil readily. The technique ensures the purity of the oil, which makes it an excellent option for your vehicle. 

Firstly, the additive feature of this oil, along with its gas-to-oil technology, ensures fuel efficiency. Studies have proven that your vehicle could increase up to 550 extra miles with this synthetic motor oil in one year. This is because the company claims your engine will be 50 times cleaner than any other motor oil.

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It protects engines against LSPI, which makes it an excellent choice for turbocharged engines too. Additionally, the oil lubricates engines readily in cold temperatures. Your vehicle will start faster and incur minimum cold-damage. Contrarily, this oil prevents evaporation in hot climates.

Here are a few specifications of this synthetic motor oil:

Volvo, FCA MS-6395, Honda/Acura HTO-06, GM dexos1 Gen 2, Ford WSS-M2C946-B1, and Chrysler MS-13340.

This synthetic motor oil exceeds the prerequisites of the following:

API SN-RC, API SN PLUS, etc. ACEA A1/B1, ILSAC GF-5.

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Pros:

  • Completely synthetic 
  • Enhances fuel economy of the vehicle
  • Engine protection 
  • It helps maintain engine quality in extreme temperatures
  • Prevents wear and tear from oxidation stability

Cons:

  • Fuel efficiency not as high as other brands 
  • Packaging below par

10. Mobil 1 (120769) High Mileage 5W-30 Motor Oil – 5 Quart

Mobil 1 (120769) High Mileage

This synthetic motor oil is an excellent option for people looking for something for engines with more than 75,000 miles on them. The Mobil 1 oil ensures extreme protection and lubrication to the engine. 

It enhances the performance of the engine while still providing it with adequate protection against sludge build-up. It is far more advanced than most other motor oils by the same brand. It works best for old engines as it prevents any pesky leaks too. 

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Leaks in the engine are controlled with the help of the boosted seal conditioner. This may weaken over time and cause leaks. However, the conditioner prevents any untimely shrinkage of this seal. The brand claims that this oil can ensure over 500,000 miles worth of protection for your engine if you choose this oil. 

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Pros: 

  • Great for high-mileage engine
  • Protection for essential engine components 
  • Sludge deposits are minimized 
  • Reduced chances of leaks 

Cons:

  • Viscosity options are not satisfactory 
  • Price changes

Synthetic Motor Oils – Buying Guide 

Engine Oil

With so many options online, you are practically spoilt for choice. However, not all synthetic motor oils are worth your money. So, before you buy any synthetic motor oil for your vehicle, you must learn more about it. Here is a comprehensive buying guide to help you with your purchase. 

RELATED: 10 Best Oil Filters

Brands

You need to pick the right brand of motor oils first. Going with a new brand that has no previous customer reviews could be a gamble when it comes to your vehicle’s engines. Make sure you only opt for synthetic motor oils from reputed brands online. 

A few profitable brands that you can consider buying from including Mobil, Valvoline, Castrol, and Royal purple. These brands have made their name in the industry and are now trusted household names. 

Affordability 

Most good things come at a price. So, if you want to prioritize your engine’s health, you might have to splurge on this motor oil. Many motor oils that cost less than $20 are generally synthetic blends. They are just as good but inexpensive. 

On the other hand, synthetic oils over $20 are entirely manufactured and are usually on the steeper end. Their quality is unmatched because of their formulas and purity of blend.  

Viscosity

Viscosity is essentially the thickness of the motor oil you use. It can be measured and written down as 5W-30, 5W-20, and 0W-20. The first digit in this number signifies the viscosity in cold temperatures, and the number at the end denotes consistency in heat. 

The viscosity of the oil is important because it determines how your engine will perform. Your engine will have to do more work if the motor oil is too thick. So, your motor oils should be consistent and not change too rapidly with temperature changes. 

Additives

Additives are extra components in the synthetic motor oil; this could be anything from corrosion inhibitors, viscosity index improvers, anti-foaming agents, conditioners, detergents, antioxidants, dispersants to anti-wear agents. Do your research well and see what works best for your vehicle.

Compatibility

Understand what your vehicle engine needs and make sure you give it that. Test both synthetic motor oil and conventional motor oil and see which one has the best effect on your machine. 

To conclude with

Synthetic motor oil has a large number of benefits over traditional oil. You can test it out on your vehicle and see if it works. Be sure to do your research well and pick the right option. The suggestions mentioned above are sure to help you too!

Synthetic Motor Oil FAQ

What brand of synthetic motor oil is best?

The debate surrounding the best synthetic motor oils is a longstanding one. However, we strongly recommend choosing any of the known brands like Mobil, Valvoline, Castrol, Liqui Moly, and Royal purple.

Is Mobil 1 the best synthetic oil?

Mobil 1 is absolutely in the top 5 of the best synthetic motor oils you can find on the market. However, if it is really best is just speculation; it depends on your car engine model. Not all engine oils are suitable for all engines.

What is the best 5W30 synthetic oil?

If you are looking for a great 5W30 synthetic motor oil, you should absolutely look into any of these brands: Mobil, Valvoline, Liqui Moly, Castrol, and Royal purple. We do recommend Castrol or Liqui Moly for most engine types.

Will synthetic oil last 2 years?

The most so-called “long-life” synthetic motor oils last up to 2 years or even longer. However, it is not recommended to use them if they are older because they will lose their performance. Check the motor oil specifications for exact information.

Written by:

Magnus is the owner and main author of MechanicBase. He has been working as a mechanic for over 10 years, and the majority of them specialized in advanced diagnostics and troubleshooting. Certified Automotive Diagnostic Technician.