Top 10 Best Oil for Duramax of 2021 – Buyer’s Guide

by Mike Constanza

When it comes to your vehicle's Duramax engine, you need heavy-duty and reliable engine oil. It is to make sure that the engine will work smoothly and perform exceptionally. Getting the best oil will guarantee that your Duramax will be protected and have a long engine life.

Choosing engine oil is undoubtedly vital primarily if you use it to carry heavy loads on a long-distance journey. However, you don't have to worry since this article prepared all the information you need to help you choose the best oil for your engine.

Additionally, tips on how you can spot the best oil and its benefit are also included in this review. Here is a list of the best oil for Duramax that the market has to offer. Check it out and learn more.

Editor's Recommendation: Top Oil for Duramax of 2021 

zzSummary Table for Top 10 Best Oil for Duramax of 2021

Image Product Name Price

Shell Rotella T6 Synthetic 5W-40 Diesel Engine Oil

Shell Rotella T6 Synthetic 5W-40 Diesel Engine Oil

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Liqui Moly Synthoil Premium 5W-40 Synthetic Motor Oil

Liqui Moly Synthoil Premium 5W-40 Synthetic Motor Oil

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Shell Rotella T4 Triple Protection Conventional Engine Oil

Shell Rotella T4 Triple Protection Conventional Engine Oil

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Valvoline Premium 5W-40 Oil, Full Synthetic Engine

Valvoline Premium 5W-40 Oil, Full Synthetic Engine

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Delo XLE 400 Synthetic Blend Oil, 15W40

Delo XLE 400 Synthetic Blend Oil, 15W40

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Our Best Oil for Duramax Reviews

Each oil has unique solutions formulated in making sure that it will help in boosting your engine's performance. Finding the best one out of hundreds of engine oils in the market can sometimes be a problem. To help you, a review of each product was made for easier selection.

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

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

The first one on this list is a synthetic diesel engine oil that ensures that your engine is cleaned and protected at all times. The oil is versatile because it can be used in both diesel and gasoline engines. It is a plus, especially if you have these kinds of engines in your trucks and other vehicles.

Using this oil, your Duramax engine will surely be durable and protected from any engine wear for a long time. It also has a triple protection technology that will shield the engine from dirt and soot that can build up inside its component.

Based on its viscosity grade, you will not have a problem when the temperature changes. It means that the engine will work smoothly even if its cold or hot weather. Aside from that, it is relatively cheaper compared to other oil you see in the market.

All in all, Shell Rotella is an excellent product, and it is one of the best oil for the Duramax engine. You can be assured now that it will work well, especially if it needs to do heavy hauling. It will also save you money since its not expensive, and it can maximize your fuel consumption.

Highlighted Features

  • 1.5% fuel economy performance, which is better than other oil
  • Advance additives to keep your engine durable for a long time
  • Makes your engine clean and protected from dirt and contaminants
  • A heavy-duty oil that is perfect every time you have a heavy haul

2. Liqui Moly Synthoil Premium 5W-40 Synthetic Motor Oil

Liqui Moly Synthoil Premium 5W-40 Synthetic Motor Oil
Liqui Moly Synthoil Premium 5W-40 Synthetic Motor Oil

Next in the list is a synthetic oil from a well-known and German-made brand. The oil greatly works in any gas and diesel engine. It is mainly made for engines with modern technology like multi-valve, timing configuration, supercharging, and so on.

If you use your Duramax engine to carry heavy loads all year out, you can rely on this motor oil to do the heavy-duty work for you. It will help your engine reach its maximum potential and improve fuel efficiency.

Even on a cold start, the oil will immediately work and lubricate your entire Duramax engine. It means that it will work perfectly even at low temperatures, which is ideal if you ride in those types of conditions. This is due to the engine's excellent cold cranking abilities and oil pumpability.

The oil will also help clean and remove any contaminants, which will help the engine run smoothly and save fuel. It will also be helpful in eliminating sludge, soot, and deposit build-ups that negatively affect the efficiency of the engine.

Aside from that, it holds up quite nicely in an extended oil change interval. You will also be amazed at how it can perfectly distribute oil during high temperatures, which can protect your engine from overheating. It provides not only high performance as a fuel but also useful in reducing air pollution.

Highlighted Features

  • It helps save fuel
  • Make your engine lubricated on a cold start
  • Works significantly on upgraded engines
  • Makes your engine work smoothly and perform better

3. Shell Rotella T4 Triple Protection Conventional Engine Oil

Shell Rotella T4 Triple Protection Conventional Engine Oil
Shell Rotella T4 Triple Protection Conventional Engine Oil

This engine oil is the improved and better version of the original predecesso. The product they have is upgraded to adapt to any engine condition, such as modern engines with low-emission, and old diesel engines.

Its protection technology works magnificently in making sure that the engine is protected from deposits and wear. This is useful in preventing extreme conditions in affecting your engine's performance. It can also prevent the build-up of soot and other contaminants, making this engine oil more efficient and more earth-friendly.

The product also shows that the oil has 50 percent resistance against oxidation, which means that it will run higher miles while its engine works on its maximum output. Since it has acid control, your Duramax engine will be protected from corrosion, which is the number one foe of engine performance.

Additional features include compatibility with different emission systems such as those that employ after-treatment technology. This product also promised improved viscosity due to enhanced oil aeration and sheer ability. The engine oil is also formulated with low ash content for the usage of the exhaust catalyst.

You will even see that the engine is performing better, even under pressure. This is the reason why this product is highly used by heavy-duty vehicles as it gives great benefits to the engine.
Highlighted Features

  • Has an excellent wear protection
  • Help engine works better even under stress and high temperature
  • It can protect the engine from sludge build-up
  • Prolong your engine life
  • Less ash content
  • Acid control for the prevention of corrosion

4. Valvoline Premium 5W-40 Oil, Full Synthetic Engine

Valvoline Premium 5W-40 Oil, Full Synthetic Engine
Valvoline Premium 5W-40 Oil, Full Synthetic Engine

The manufacturer is also one of the companies that are continuously providing premium engine oil in the market. One of their products is this high quality synthetic oil that helps protect your engine component from wear, deposits, and soots.

Aside from that, you will be assured that no problem will occur even if you ride it in hot or cold temperatures. This engine oil will make your Duramax respond faster and better in any kind of weather conditions.

It also has a high TBN or Total Base Number, which helps to combat acidic materials and contaminants in the engine. It will help in cleaning your Duramax engine that will increase its performance. Aside from that, it helps improve your fuel economy, helping you save money while reducing ecological footprints.

Some of the features include improved protection against oxidation of the engine. You can also see that the product can show excellent performance in both standard and extended intervals. It is also compatible with modern engines like EGR or Exhaust Gas Recirculation and DPF or Diesel Particulate Filter.

This engine oil also gains recommendations from a large number of engine manufacturers. As a whole, this oil is coined to be one of the leading products in the market due to the benefit it can offer for the vehicle's engine.

Highlighted Features

  • Excellent protection from wear, deposits, and soots
  • Faster engine response in any kind of weather conditions
  • Recommended by many engines manufacturers
  • Compatibility with other modern engines
  • Better fuel economy percentage

5. Delo XLE 400 Synthetic Blend Oil, 15W40

Delo XLE 400 Synthetic Blend Oil, 15W40
Delo XLE 400 Synthetic Blend Oil, 15W40

If your Duramax needs to do heavy work or go on a long journey with a heavy load, then this synthetic blend oil can help you out. This heavy-duty oil will make your heavily used engine be lubricated and cleaned, making sure that it will do the job correctly while prolonging its life.

Aside from that, its cleaning additives will help reduce downtime in your Duramax engine and lessen your maintenance cost. It can easily handle any soot and rust that can build up and harm your engine's component.

The product is also powered by ISOSYN Advanced Technology that works best in engines in highway applications. Its manufacturer also ensured that it has low greenhouse gas emission and can accommodate engines with selective catalytic reduction (SCR) and Diesel Particulate Filter (DPF).

It boasts an exceptional oil pumpability flow rate to maintain an excellent viscosity level. You will also be amazed by its long drain ability, providing high performance for both off and on-road engines. This product also promised maximal utilization and reduced downtime due to the active protection mechanisms.

You can also find it more preferable than other engine oil because of its price. Its container might give you a headache as its handle design will make pouring a problem. However, the product is definitely worth every penny due to its features and excellent performance.

Highlighted Features

  • A high-quality synthetic-blend oil
  • Better soot dispersant and wear protection
  • It has excellent cleaning additives making sure that your engine will last long
  • Compatible with engine compliant to lower emission systems

6. Mobil Delvac 1300 Engine Oil

Mobil Delvac 1300 Engine Oil
Mobil Delvac 1300 Engine Oil

This product will surely be heaven-sent for your Duramax powered engine car since it is classified as high performing engine oil with excellent characteristics. To begin, you will be surprised by its multigrade features that offer maximal oil pumpability and cold cranking abilities during low or cold temperatures.

If you're looking for a flexible product, you can vouch for this oil that promises delivery of excellent performance even in modern low emission engines that use Exhaust Gas Recirculation. It is also applicable to engines with diesel oxidation catalysts and After-Treatment Systems with Diesel Particulate Filters.

Not yet convinced? You will be when you know that it can deliver good performance under harsh conditions. This product makes sure that your engine will be protected even when used in severe road conditions. Hence, it can support heavy-duty applications such as mining, construction, and agricultural services.

Due to superb results, this product exceeded requirements in CI-4 PLUS, API CJ-4, and original equipment manufacturer (OEM) service categories. It can also accommodate cars with demanding engine oil needs such as Mercedes Benz, Navistar, Volvo, etc.

The engine also meets the specification set by API SM for both mixed fleets and gasoline engines. It just proves that this engine is carefully crafted to ensure quality performance for any Duramax engine.

Highlighted Features

  • It can accommodate different engine needs of your vehicles
  • Passes specification requirements of API SM
  • Offers maximum oil pumpability in cold temperature
  • Equipped with cold-cranking capabilities
  • Exceeded standards set by service category units
  • Support engine well even in heavy-duty work and extreme conditions

7. Shell Rotella T5 Engine Oil, SAE 15W-40

Shell Rotella T5 Engine Oil, SAE 15W-40
Shell Rotella T5 Engine Oil, SAE 15W-40

Another product that can be trusted by drivers for their Duramax engine, which is powered by triple protection plus technology. This feature found in this oil is a combination of premium additives and synthetic base oils that actively combat engine wear, oil deposits, and engine breakdowns.

The product is synthetically blended, which is equipped with components that can help protect the engine from breakdown while also extending its life for maximum usage. It also provides excellent low-temperature flow and sustains great viscosity control in warm temperature.

You can also expect superb cold-cranking abilities and great low-temperature pumpability. It means that engine oil can reach essential engine parts quickly, even in cold temperatures. Due to this, it can protect the engine parts by minimizing wearing time and make heavy-duty engine work easier during harsh conditions.

And the product is also formulated with low ash content to secure the particulate filter, usually set up on modern emission vehicles. It can accommodate engines that require CJ-4, API CK-4, and CH-4 engine oil in terms of viscosity grade.

If you are looking for something that helps you save up, this product shows that it can produce fuel economy up to 1.6 percent. Not only that, but you will also definitely get your money's worth since the product can be used in different heavy-duty works.

Highlighted Features

  • Equipped with Triple Protection technology
  • Ensures that engine deposits will be reduced for better performance
  • Met wear requirement for API CK-4 engine test
  • Crafted for engine doing heavy-duty works
  • Comes with an improved oxidation process

8. Royal Purple 04154 Oil, 15W40, One Gallon

Royal Purple 04154 Oil, 15W40, One Gallon
Royal Purple 04154 Oil, 15W40, One Gallon

It is a high-quality oil that can improve your diesel and gasoline engines. This product uses high-quality oil with additional suitable additives, ensuring increased engine performance and excellent protection.

Moreover, it is highly recommended as its protection is three times stronger compared to other oils in the market. The additives on the oil can also stop any metal to metal contact, and it makes sure no rust will build up inside your Duramax engine.

With its cleaning efficiency and improved protection, it can perform effectively for a long time, even in the old Duramax engine. The formulation can also flush away sludge and build up in your engine. It has ZDDP additives that help prolong the life of the emission catalyst system, which is present in most modern engines.

If you want to use this oil in a new vehicle or as an upgrade, there will be no issues since it is highly compatible with other synthetic or mineral oil. However, it is recommended to wait out until your engine reaches 8000 miles or more to change it with this oil.

This product is also a good choice since it meets the strict standard by Dexos11 and ILSAC GF-5 in terms of performance requirements.

Highlighted Features

  • Excellent protection from wear and rust
  • Increases fuel efficiency
  • Prolong the life of the catalyst emission system
  • Compatibility with other fuel that has ethanol
  • Three-time more potent compared to other products

9. Valvoline Premium Engine, SAE 15W-40 Engine Oil

Valvoline Premium Engine, SAE 15W-40 Engine Oil
Valvoline Premium Engine, SAE 15W-40 Engine Oil

If you are looking for a trusted brand in terms of results, then you should definitely check out this product. This engine oil proves consistent performance proven in field test drives. Not only it has excellent TBN retention, but it also boasts high fuel economy potential while providing engine protection.

Duramax engine users will definitely like its additional features, such as outstanding soot control and impressive viscosity maintenance. Due to this, the product can provide the strict needs of most modern car engines with DPF and EGR systems.

You will be ensured that this engine oil can sustain performance in the standard and extended intervals. To add more, the product is well received by engines such as Mack EOS-4.5, Cummins CES20086, and others. It also meets service standards for CJ-4/SN, CH-4, and CI-4 Plus.

Other additional features of this oil include improved valve train for wear protection and helps control fuel consumption. It's also equipped with a synthetic base that results in a quick start of the engine in freezing conditions. This product also ensures to reduce the build-up of carbon and inhibit corrosion.

The product will surely give the care that your engine needs, making your engine works faster and last longer. By using this product, you will not worry about your engine status even when used in harsh conditions.

Highlighted Features

  • Comes from a brand trusted by popular engine manufacturers
  • Offers quick and safe start of the engine during the freezing condition
  • Provides protection against oil oxidation
  • Ensure that engine parts will be safe from deposit build-up and engine wear
  • High performance in both low and normal weather conditions

10. Shell Rotella T6 Full Engine, Heavy Duty Engine Oil

Shell Rotella T6 Full Engine, Heavy Duty Engine Oil
Shell Rotella T6 Full Engine, Heavy Duty Engine Oil

If you're looking for a reliable product for your Duramax engine, look no further since this engine oil is the one for you. You can expect that it can provide maximum protection for your engine against harsh conditions. It can also accommodate the needs of the modern engines that support low emission.

This product also boasts its low ash formulation that ensures that your particulate feature and Exhaust Gas Recirculation will be protected. The engine oil is also engineered to be compatible in most emission control systems while providing excellent performance.

With its multi-functional additives and base oils, you will be impressed with the level of protection it gives to reduce contaminant build-ups such as soot and deposits. It also improved heat resistance of the engine while also maintaining good viscosity grade due to excellent sheer ability.

And it is also on top in terms of efficiency, with about 1.5 % enhanced fuel economy. It can help you save money because of the reduced fuel consumption. The product is also equipped with advanced technology to help sustain that the engine falls within emission standards.

Moreover, this product is definitely a win for your Duramax engine due to the benefits it can provide while also helps in saving your money. Once you use this, you will be secure that it can accommodate heavy-duty works such as those vehicles used in construction, quarrying, and agricultural services.

Highlighted Features

  • Improves fuel economy
  • Enhanced wear protection even in harsh conditions
  • Great sheer stability
  • Compatible in most emission systems
  • Good control for soot and deposit build-up
  • It can support engine used for heavy-duty work
  • Resistance against heat build-up

Things to Consider before Buying Oil for Duramax

Best Oil For Duramax
Best Oil For Duramax

Choosing the best oil for the Duramax engine can be an intimidating task for users, especially for beginners in the engine world. However, this will not become a problem if you have a guide to help you select the correct product. If you're willing to learn, this guide is for you.


If you're buying engine oil, you will definitely meet the term viscosity grade when purchasing. Viscosity refers to the rate of flow of oil at a specific temperature. Oil with a lower grade or thin oil generally flows quicker into the engine at low temperatures.

Understanding the viscosity grade is crucial since it will tell you how fast the oil will be poured in the engine, reducing the friction and lowering the time for starting the car in cold weather. It is also essential that the oil can sustain this viscosity even after a long period of time.

When looking for oil, you should check your car's manual to choose the right viscosity grades. You should also take into consideration where you will be using your vehicle. Thin-oil is better at a lower temperature, while thicker oil is better suited in higher temperatures.


Most engine oil manufacturers have their own blend of additives in their formulation. This additive helps enhance particular properties to help the engine work better.

Some additives can help clean the engine so it will work efficiently and make sure that the oil won't get too thin when the temperature gets too high and more.

Each additive is helpful, but keep in mind that you need to get the oil with the right additives for your Duramax engine. Evaluate what your engine wants and choose the engine oil that can address your needs. Some examples of different categories of additives are as follows:

  • Detergent - Additives use to prevent the build-up of rust, deposit, and soot on the surface of the engine.
  • Dispersant - This helps prevent the formation of solid particles by dispersing them in a solution. Thereby preventing sludge formation in the engine.
  • Antiwear Agents - It is used to protect the metal surface, especially when the lubrication films are not working.
  • Viscosity Improvers - Refers to additives that can prevent thinning of oil's viscosity in high temperatures.
  • Corrosion Inhibitors - This reduces the accumulation of water or moisture to prevent rust formation.
  • Friction Modifiers - These additives are usually confused with antiwear additives, but it primarily functions in preventing friction in the engine part. This can positively affect fuel economy and help save fuel when used.


If you want to change your current oil to a new one, you need to check if the new oil is compatible with your existing oil. If it's not, then you need to drain the current oil inside your engine. This is to make sure that there will be no problem when you use a new oil.

Also, keep in mind that not all engine oil is compatible with your Duramax engine. You need to make sure that you only use what is suitable for your engine. Remember to check your owner's manual to know which type of oil can be used in your engine.

Fuel Efficiency

Fuel efficiency refers to the distance your car covered burning a specific amount of fuel. The more efficient your engine is, the more you can save up since a lesser amount of fuel will be used. It is essential since fuel is a valuable resource that affects the economy and the environment.

Good engine oil can positively affect the fuel economy because it can flow in the engine faster, making it less hot. If the motor is at the right temperature, it can do its job more efficiently and will not harm its part. Hence, it is crucial to look for engine oil that promises a higher fuel economy percentage.

Purpose of Driving

Getting the right oil can help you make your engine perform better. Hence, it is crucial to select engine oil depending on the type of workload.

This is helpful, especially if you use your engine in carrying or pulling heavy loads. Due to this, you must look for best-suited oil that can do heavy-duty work even in harsh conditions.

What Are the Benefits of Using Oil for Duramax LML

Here are some of the benefits of using oil for your Duramax engine. Read on.

It Makes Your Engine Last Longer

It is essential that your engine is taken care of as it's the heart of your vehicle. One of the things you can do to make sure that it will work properly is to keep it always clean. In that aspect, the engine oil will help you with that.

Diesel oil or engine oil has natural solvency, which will help you clean and remove any contaminants inside your engine. Once the dirt and soot are removed, the engine and its other components will work better. This will make the engine more efficient, which will make it last longer.

Help Engines Perform Better

Aside from making it clean, which will make it perform better, the oil can help boost the engine itself. It makes the engine work smoother and with more power, which is needed when a vehicle carries heavy loads on long-distance journeys. This is one of the things you need to check when searching for the right oil for your car.

Better Fuel Mileage

Also, one of the things an engine oil can do is to improve the mileage and lower fuel consumption of your engine. This will save you money for your gas and will make your vehicle drive more distance.

Extend the Time You Need to Change Oil

Last but not least, oil can also help you extend the time when you need to change your oil. Depending on the vehicle you have and the oil you purchase, it can make you drive a long distance before your engine oil needs changing. It will save you money from buying oil and lessen the times you need to change it.

FAQs : Frequently Asked Questions & Answers

FAQs : Frequently Asked Questions & Answers
FAQs : Frequently Asked Questions & Answers

Here we have the most commonly asked queries regarding the best oil for Duramax:

1. What is engine oil?

Engine oil or motor oil is a formulation that helps your engine work better and smoother. It lubricates the engine so it can perform exceptionally. The oil can also help in cleaning your engine and make it last longer.

2. When is the best time to change the oil?

To know your schedule, you can check your owner's manual. Usually, it should be changed when the vehicle goes 5,000 miles, but you can do it more frequently if your vehicle needs to do heavy hauling and go offroading.

3. How long can you store it?

The motor oil's shelf life can last up to 5 years, but it can change depending on where it is stored. Temperature, oxygen, water, and other things can negatively affect the quality of the engine oil. It is especially true if it is out in the open or not properly stored.

4. Difference between diesel oil and fuel oil?

Diesel oil is similar to motor oil, engine oil, and diesel engine oil, which lubricates your engine to work better. On the other hand, fuel oil is the one that powers your engine for it to move.

5. What will happen if you forgot to change your oil?

If you do not change the oil, the engine will get too hot, which can result in malfunctioning.

It will make your engine wear faster and can destroy your engine ultimately. Once it stops, you need to replace it, and that requires money. Hence, it is crucial to change your oil regularly so you can keep your engine better.

Final Words

It's necessary to maintain your engine, so it will work better. However, you need to be informed about the things to consider in buying oil to support your engine's needs. This is crucial when getting the best oil for duramax engine for maximum usage.

Additional Resources:

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About Mike Constanza

For years, Mike had always told everyone "no other sport like baseball." True to his word, he keeps diligently collecting baseball-related stuff: cards, hats, jerseys, photos, signatures, hangers, shorts (you name it); especially anything related to the legendary player Jim Bouton.

Mike honorably received Bachelor of Science degree in Business Administration from University of Phoenix. In his graduation speech, he went on and on about baseball... until his best friend, James, signaled him to shut it.

He then worked for a domain registrar in Phoenix, AZ; speciallizng in auction services. One day at work, he saw the site pop on the for-sale list. Mike held his breath until decided to blow all of his savings for it.

Here we are; the site is where Mike expresses passion to the world. And certainly, he would try diversing it to various areas rather than just baseball.

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