Best Synthetic Oil For Diesel Engines #1 Review In 2020

In this comprehensive buyer guide, you will ​find out what synthetic oil is and what it does for your engine and car. This post also includes the vital features that you need to consider in choosing the best synthetic oil.

To help you ​choose the best synthetic oil for a diesel engine, we have reviewed three of the best.


What Is Synthetic Oil?

Synthetic Oil


​Synthetic oil contains more ​refined base oils ​than ​those used in traditional mineral oils, providing you the best protection and performance. There are lots of benefits that keep your engine performing at its best for years. Synthetic oils are getting increasingly popular these days.

It is ​made from crude oil that comes from the ground. The only difference with synthetic oil is that it is made from a more advanced refining process, is of high quality, and is purer than traditional mineral oils. The oil will not only remove impurities from the crude oil, it also ​contains ​molecules ​that provide the highest level of protection and performance.

The Factors You Need to Consider Before Buying

The Factors Need to Consider

You have to keep in mind that it is not a good idea to decide right away and buy the first product that you see online. Most of the time, they are not the right product for your car. To help you decide, here are some factors that you can consider.

1. Cost

Some people think that it does not matter how expensive the product is as long as it provides the service that you need. But we think it is an important factor. You wouldn’t want to spend a lot on a product that you are not sure of.

Also, it is important to know that full synthetic engine oils cost ​more ​than ordinary or even synthetic combinations.

2. Viscosity

The main determining factor in choosing the best synthetic oil is the viscosity. The viscosity will depend on the type of ​vehicle and the weather conditions.

If your car is the performance type, some oil will provide added protection. Check the original recommendation of the manufacturer concerning the viscosity grade.



This is ​vital, as it will determine the temperature of your engine. You need to choose the oil that can provide the best performance, even under pressure.

3. Cleaning Capability

The most important factor when changing oils is cleanliness. Make sure that you choose the diesel oil that has the best capability to clean your engine.

4. Compatibility

Keep in mind not all vehicles are​ suitable for all diesel ​oils. There are some that perform well with a gasoline engine and require various types of lubricants. Make sure that your diesel oil is compatible with your engine.

5. Protection

The diesel engine oil you choose should not damage your engine. It should provide optimum wear protection to extend its lifespan.

6. Versatility

Pick diesel engine oil that is versatile and can be used in a number of ways.

7. Efficiency

Before deciding which oil to buy, it would be best to consider how ​engine oil can help you to provide more efficient fuel consumption.

Top 3 Best Synthetic Oil for Diesel

**Below, you'll see more detailed reviews, but you can also click the links above to see current prices and read customer's reviews on Amazon.

Mobil 1 120764 Synthetic Motor Oil

Via Amazon

​One of the most popular synthetic oils on the market today is the Mobil 1 120764. The product ​is an advanced synthetic motor oil manufactured to keep your engine clean and performing at its best. It provides protection against wear. The Mobil 1 meets the ILSAC GF-5 performance standards and is approved by the General Motors.

The product exceeded the requirements of the industry’s tough standards and outperforms ​traditional motor oils. Recommended for all types of vehicle, even those high-performance, turbocharged, diesel multi-valves, fuel injected engines and supercharged gasoline.

The advanced formula of Mobil 1 helps prevent the sludge build-up and deposit to make sure your engine’s life is extended.


  • Superb viscosity control
  • Excellent low-temperature capabilities
  • Performs well in colder area
  • Can turbocharged newer engines
  • Easy to use
  • Aids fuel economy


  • Not recommended for aviation or 2 cycle engines

Royal Purple 51530 High- Motor Oil

Via Amazon

The Royal Purple is a combination of premium base oils with additive technologies to produce high-performance motor oils that boost engine performance and offer great protection. There are no special procedures needed when upgrading to Royal Purple.

It is fully compatible with mineral as well as with other synthetic oils. The manufacturer of the Royal Purple suggests that you wait until it is ​time for the first scheduled oil change before using Royal Purple.

Royal Purple is available in different viscosity levels of API-licensed motor oils. To enable ​the best break-in of the engine, wait 8000 to 10000 miles before you use Royal Purple in diesel engines.


  • Improved wear protection
  • Best corrosion protection
  • Enhanced compatibility with fuels that contain ethanol
  • Boost fuel efficiency
  • Improved protection of the costly catalytic emission system


  • Without dispenser spout

Shell Rotella 550019921 T6 5W-40

Via Amazon

This product has low ash technology and a versatile additive, which is manufactured to provide protection. Shell Rotella 550019921 offers enhanced fuel economy ability of 1.5% without affecting engine protection or durability. It improves wear performance, and increases the level of protection against bad engine wear ​compared to the previous generation.

It has advanced multi-functional dispersant additives together with synthetic base oils that offer an enhanced level of protection to fight soot, dirt and other contaminants. The Shell Rotella has an advanced low-ash formulation that controls blocking of or poisoning the exhaust after treating the devices. This helps maintain the car emission compliance and engine fuel efficiency.

Heat resistance improved. It prevents breakdown by providing protection in the service interval.


  • Enhanced fuel economy
  • Helps the engine work continuously quietly and smoothly
  • Amazing oil for most vehicles using diesel engines
  • Start-up is easier and fast


  • The price is not reasonable
  • The pressure is slightly increased

The Best Synthetic Oil For Diesel Engines on the Market!

After evaluating the top 3 best synthetic oil for diesel engines, we recommend Mobil 1 120764 Synthetic Motor Oil. The product possesses all the qualities that one has been looking for in synthetic oil for a diesel engine. You will not have any issues in start-up even during the cold weather. It prevents the dirt and sludge from accumulating ​and enhances lubrication and friction properties.

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