A Guide to Finding the Best Diesel Engine Oil In The Market

A diesel engine oil is an important lubricant to your car's engine. With the hike in gas prices, getting your car's engine with this oil can save you a great mileage and make you enjoy driving your car. You don't want to be having stresses from your engine as a result of wear and tear of the metals causing your engine to malfunction. Even though there may be different brands available with high prices, still filling and changing your engine oil with the best diesel engine oil can be a wise decision and a for the longevity of your car's engine.

** Below, you'll find our more detailed reviews by click in "Reviews" column, but you can also click the links above to see current prices or read customer reviews on Amazon.com.

What is a Diesel Engine Oil?


A diesel engine oil is a fluid that keeps the insides of the engine in order. Keeping things in order simply means that it lubricates the parts of the engine so as to avoid the filling effect on the load bearing surfaces of the engine. When there is a metal to metal contact inside the engine without the presence of an engine oil, there is going to be a wear and tear due to friction.

An engine requires a regular oil change and the more you change it, the longer the life of your engine. Once you understand that the temperatures and pressure inside an engine are high, you will realize that oil can easily be contaminated. And when it does, it will exhaust the engine mostly the combustion chamber as it tries to burn fuel, That is why sometimes you notice a white smoke coming out of an exhaust because the engine oil has gone bad.

The main component that rates a diesel fuel is called Cetane or isocetane which is a gas that has a colorless property. Cetane is the reason behind why diesel engine oil is more preferred than the usual gasoline oil because it can ignite and burn very easily with less heat.

A basic diesel engine oil is available in two grades which are either 1-D or 2-D which have different isocetane numbers and if one has a higher number, it will make the fuel to be a little more volatile. Diesel 2-D is mostly preferred to be used in the normal driving and on the heavy load trucks because of its low volatility property.

Viscosity is another important property in a diesel engine oil. It is the measure of the inability of the fluid (oil) to flow. So when diesel oil is exposed to cool temperatures, it becomes thick like a gel and its viscosity rises. Diesel 1-D is mostly preferable on cool temperatures due to its less viscous property. So to make the right diesel engine oil, you can make a concoction of the two grades of oil.

Advantages of Diesel Engine Oil

  • If you are thinking about an awesome mileage, then you should probably go for a diesel engine oil than gasoline because it offers a higher percentage of fuel economy compared to gasoline.
  • Diesel engine oil has a greater ignition tendency, so you won't require a booster or a tune- up unlike gasoline whose rating is octane, and its oil inability to self-ignite is high.
  • You don't have to worry on a sudden surge of high compression when it comes to a diesel engine oil because the technology used in creating it ensured that it could withstand that.
  • It reduces the temperature through the process of conducting any heat away from that result from the burning of fuel in the combustion chamber thus saving a lot of energy.
  • It minimizes the chances that a metal inside the engine encounters another metal, creating a filing action hence eliminating wear and tear. Your engine won't experience a frozen piston or stuck piston rings.
  • It maintains the cleanliness inside your engine since it is able to remove all the impurities to the filter. Your engine will be free from anything foreign that can damage it.

See more about: Fuel Injector Cleaner and Diesel Fuel Additive

Diesel Oil or Gasoline

The anti-wear in the diesel engine oil enables the catalytic converter to transform any toxic emissions from the engine into harmless gasses before they are exposed to the environment, but gasoline lacks the anti-wear. So using gasoline means that the catalytic converter will have many problems because there will be no zinc dialkyl dithiophosphate that can act as an anti-wear. So I would highly recommend diesel engine all every time.

The Top 5 Best Diesel Engine Oil with Reviews

Hot Shot's Secret DDD Diesel Oil and Fuel Additive

Every car owner's dream is to have a longer lasting car engine, but you cannot achieve that dream without using the right type of diesel engine oil that is equal to the task of protecting your engine at all times. Neither do you want to be driving with disturbing noises coming out from the insides of your engine because either your drag, lifter or a valve is too dry. That is why we have Hot Shot's Secret DDD Diesel Oil and Fuel Additive to serve your engine the way it deserves.

Hot Shot's Secret DDD Diesel Oil and Fuel Additive has all the necessary engine cleaning product that will make sure your tank is sparkling clean and that no impurities through the oil filter damage your engine. Its power has been accelerated, and its resistance to compression is high.


  • Keep your engine clean
  • Has a high resistance to compression and its power is high
  • Prevents unpleasant noise from the engine parts
  • Reduces wear and tear from metal to metal filing action
  • Has money back guarantee


  • Low quality
  • Shows no sign of change when used
  • Expensive

Liqui Moly 2332 Leichtlauf High Tech 5W-40 Engine Oil

One thing you have to be keen on is the change in environment and the effect it has on your car's engine. You don't want to be having a hard time trying to start your car in the morning because the engine oil inside has turned into a gel and has become highly viscous. You need an engine oil that can well adapt to such changes and not cause you headaches instead. In short, all you need is Liqui Moly 2332 Leichtlauf High Tech 5W-40 Engine Oil because your engine can be guaranteed a lubrication in both the high and low temperatures. With Liqui Moly 2332 Leichtlauf High Tech 5W-40 Engine Oil you won't think about going for regular car servicing because your engine will be well protected at all times and the good thing is that it is compatible with all the available engine oils.


  • Stable in all temperatures
  • Keeps your engine clean
  • Affordable
  • Saves on fuel
  • Highly accepted by most vehicle manufacturers
  • Reduces on pollution


  • No guarantee

Red Line 21405 15W-40 Diesel Oil

Do you have a variety of car types and sizes and you are wondering which diesel engine oil is the best for all of them? Buying for each engine can be quite expensive and non-resourceful. When you think of an engine oil with additive technology, Red Line 21405 15W-40 Diesel Oil comes first. It accommodates both the medium-sized and heavy-duty trucks. It can practically be used on a fleet of vehicles, and it has the acid neutralizing ability which ensures that your engine is safe and clean at all times.


  • Can be used on a variety of cars
  • High resistance to heat malfunctions
  • Has acid neutralizing ability
  • Cleans and protects your engine
  • Affordable
  • Efficient


  • No negative reviews available at the moment

BestLine 853796001429 Premium Synthetic Diesel Engine Treatment

BestLine 853796001429 is an ideal diesel engine oil that offers all the protection and cleanliness that your engine deserves. It performs like no other engine oil ensuring that it lubricates, conducts away heat hence economizing on fuel and protects the valves and metals inside from wear and tear. It also reduces pollution of the environment.


  • Has cleaning and protection properties
  • Reduces pollution
  • Minimizes high temperatures and friction
  • Reduces wear and tear
  • CheapImproves performance


  • Misdirection on packaging

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

If you have heavy commercial vehicles, then Shell Rotella (550019921) is the perfect diesel engine oil to use in your vehicles. Shell Company is a trusted manufacturer and processor of petroleum products that protects and prolongs lives of vehicles.

Shell Rotella features a low- ash additive technology that protects your engine on every driving experience. It has an anti-wear that ensures that toxic emissions are neutralized first before they are released to the environment.


  • Maintains the efficiency of your vehicle
  • Protects your engine against impurities and extreme climates
  • The low-temperature flow is great
  • Cheap


  • Poor packaging
  • Low lubricity


Every car's engine deserves regular maintenance and oil change for its longevity. However choosing the right diesel engine oil for your vehicle can be sometimes daunting. I would advise that you read the package you have bought to ensure that it is the right fluid and not for the fuel. Red Line 21405 15W-40 Diesel Oil seems to be the best diesel engine oil due to its all-round capabilities and its affordability.

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