7 Best Oil for 5.9 Cummins in 2022 [Oil Viscosity Chart]

The oil inside your 5.9 Cummins does a lot more than transferring energy. Whether it is about reducing the friction or protecting your engine from all that corrosion, the best oil for 5.9 Cummins can make everything better. However, getting hands-on with that best one is a challenge itself.

Not to mention, the local market is swarming with cheap and low-quality engine oils. As a result, you might get manipulated and bring harmful engine oil instead. So, how can you decide what to choose?

Well, don’t you worry at all! We are here to answer all your questions and take your 5.9 Cummins at its best. Therefore, start with the table below to get an overall idea about the products.

 Top 7 Oil for 5.9 Cummins-Comparisons

Product NameViscosityTypePrice
Castrol 06249 Edge Motor Oil5w-40Full Synthetic
AmazonBasics High Mileage Motor Oil5w-40Full Synthetic
Royal Purple Oil15w-40Synthetic
Rotella Shell Rotella T6 Diesel Engine Oil5w-40Full Synthetic
Valvoline Daily Conventional Motor Oil10w-30Conventional
Rotella T6 Diesel Engine Oil15w-40Full Synthetic
Schaeffer Manufacturing Co. SynShield10w-30Synthetic

Top 7 Oil for 5.9 Cummins

1.Castrol 06249 Edge Motor Oil

Castrol 06249 Edge Motor OilIf you are looking for the best engine oil for 5.9L Cummins, the Castor Edge motor oil might be the best choice. With tons of exciting features, the brand stands above any oils in the market.

With the impressive protective-measures, you get a rust-free and corrosion-free engine. Also, it provides the necessary lubrication to your engine and helps it to work smoothly.

Moreover, you get cleaner fuel passing through your engine. Not to mention, it is 42% better in fighting against the deposits that steal the power of your engine oil.

Features & Benefits

Superb protection

With this oil, you will get total protection against oxidation, wear, or and corrosion. Therefore, your engine can serve you even longer by using this oil.

Better gas mileage

The Castor Edge motor oil does not use any crude oil in its mixture. And so, you get better mechanical performance with it.

Excellent lubrication

Unlike any other cheap-quality engine oil, the Castor edge provides maximum lubrication to your engine parts. As a result, you enjoy a smoother and hassle-free ride.


  1. Does not include crude oil
  2. Takes down build-ups
  3. Longer lifespan
  4. Convenient operating temperatures
  5. Ideal for cold weather


  1. Costs a bit more than others

2.AmazonBasics High Mileage Motor Oil

AmazonBasics High Mileage Motor OilFriction issues are pretty common in 5.9L Cummins. However, with the AmazonBasics High Mileage Motor Oil, that does not seem like a problem. With the exhaustion-reduction features, the oil can cut down the friction significantly.

Not just that, you get to enjoy a long changing interval due to the viscosity control. Nonetheless, it takes care of any heat change and keeps your engine safe from any sort of breakdown.

Furthermore, the oil acts as a protective layer on your engine. Hence, you get superior protection against rust, dust, and corrosion. In total, it is the best motor oil for 5.9 Cummins at the best price range.

Features & Benefits

Reduced exhaustion

The oil reduces exhaustion and ensures that your engine gets to face minimum friction. Thus, it provides you a smooth ride every time.

Superior resistance

The additives of the oil take full control of the viscosity and prevent your engine from any thermal-breakdown.


The oil includes superior protection against corrosion and oxidization. Therefore, you get a longer lifespan as well as durability.


  1. Reduces the engine wear
  2. Consistent flow
  3. Superior protection
  4. Longer changing interval
  5. Act as an engine block heater


  1. The bottle might spill oil

3.Royal Purple ROY04154 04154 15W40 Oil

Royal Purple ROY04154 04154 15W40 OilThe Royal Purple is considered the best synthetic oil for 5.9 L Cummins for a bunch of reasons. First of all, the cold flow of this synthetic motor oil makes it steady and consistent even in the coldest temperature.

Secondly, the oil comes in a bottle of 32 fluid ounces. Not to mention, it is equally compatible with CK-4, CJ-4, CI-4, and CI-4 Plus types. Now, thirdly, the viscosity level of the oil keeps you safe at any temperature. Therefore, it is a great plus point.

And lastly, the oil includes the best quality additives in it. And so, they work on the entire flow and elongates the intervals of changing your engine oil.

Features & Benefits

Outstanding protection 

The oil has a corrosion-free design. Hence, it adds to the durability and longevity of the product.

Universal fit

Unlike most other motor oils, you will get a universal fit with it. So, the feature makes your replacement job hassle-free and super-easy.

Impressive cleanliness

The detergents in the oil work on the deposits and make sure that your engine stays clean all the time.


  1. Goes for a long time
  2. Highly compatible
  3. Prevents clogging and build-ups
  4. Less friction and smoother running
  5. Elongates drain-intervals


  1. Has some leaking issues

4.Rotella Shell Rotella Diesel Engine Oil

Rotella Shell Rotella Diesel Engine OilAre you tired of the viscosity-loss and the uneven performance of your 5.9L Cummins? Well, all you need is to grab the Rotella Shell engine oil and get rid of any viscosity-related issue.

Also, it is the best diesel oil for 5.9 Cummins for the unmatched protective services. Therefore, you can protect your engine from any possible threat with the help of this engine oil.

Although the oil is quite versatile, it is highly compatible with the SAE 5W-40. So, pair it up according to the manual of your engine for the best results.

Features & Benefits

Superb fuel-economy 

The fuel economy of this engine oil is almost 1.5% better than the regular ones. So, you can save a lot of money and effort by switching to it.

Improved dirt-technology 

The oil-additives include advanced dirt-technology. Thus, it can get rid of any sludge or dirt particle from your oil without even disrupting its efficiency.

Prevents viscosity loss

With this engine oil, you will be able to minimize the amount of viscosity-loss. As a result, you will notice better stability and faster action.


  1. Smooth and long-lasting
  2. Blocks all contaminants
  3. Maintains pressure of engine oil
  4. Protects equipment
  5. Excellent economic-performance


  1. Might seem a bit dirty after a while

5.Valvoline Daily Conventional Motor Oil

Valvoline Daily Conventional Motor OilThe first thing that you might notice is the super-smooth action of this Valvoline Daily Conventional Motor Oil. The reason behind it is the additives that provide sufficient lubrication to the engine.

Secondly, cleanliness is another specialty of this oil. As a result, you get rid of any harmful contaminants without even putting in any effort. And finally, the oil does a great job in maintaining the appropriate heat-level.

Nevertheless, you get to be free of any worries about facing a thermal breakdown. Therefore, get this best engine oil additive for 5.9 Cummins and maximize the potential of your engine.

Features & Benefits

Removes sludge

Because of the added detergents, the oil is capable of removing any sludge or impurity that lies in your existing engine oil.

Maximum protection

The oil controls the heat level of your engine and balances out any sudden fluctuations. Thus it keeps all your engine parts good as new.

Smooth action 

The additives of the oil have high-quality resistance. And so, it can protect your engine from any sudden breakdown.


  1. Durable and versatile
  2. Additional wear protection
  3. No room for dirt
  4. Light and convenient


  1. Oil might seem a bit thin

6.Rotella T6 Diesel Engine Oil

Rotella T6 Diesel Engine OilIf you are looking for an option that is compatible with different heat ranges and still has incredible efficiency, this Rotella T6 Diesel Engine Oil is everything you need. From heat protection to super-smooth action. This oil excels in every aspect.

Not just that, the advanced design makes sure that all of your engine parts get the maximum protection. Not to mention, it blocks away from any contaminants from the oil for you.

As a result, you can save both time and money by using this oil. Therefore, go ahead and grab this best oil for Dodge Ram 5.9 Cummins.

Features & Benefits

Excellent resistance

The unmatched resistance of this engine oil makes sure that you get a longer lifespan with maximum durability.

Developed fuel-economy

If you compare it to the SAE 15W-40, you will get a 1.5% better fuel economy with this engine oil.

Triple protection 

Because of the triple-protection formula of the additives, you get total protection against rust, corrosion, and oxidization.


  1. Stable and consistent
  2. Budget-friendly option
  3. Long-lasting service
  4. Gets rid of dirt


  1. The design of the bottle is not the best
  2. Has pouring issues

7.Schaeffer Manufacturing Co. SynShield

Schaeffer Manufacturing Co. SynShieldWhen you start using the Schaeffer Manufacturing engine oil, you will see some distinct differences in the high performance of your engine. For starters, you will observe well-defined thermal stability.

As a result, you can work in different climatic conditions without any hassle. Again, the protection against oxidization is a prominent feature of the oil. Moreover, you don’t even need to spend on an oil filter for 5.9 Cummins.

Not to mention, the fuel economy does not compromise with the durability of it. Therefore, for the cleanest and smoothest performance, pair up this engine oil right now.

Features & Benefits

Best friction-control 

Because of the added micron, you get the maximum friction-control with this oil. As a result, you don’t have to face any jamming issues with your engine.

Great protection

The oil makes sure that you face minimum viscosity loss. Hence, all of the parts of your engine get superior protection against any harmful situation.

Super-smooth action

The oil can resist any breakdown because of the convenient heat range of it. And so, it results in a smooth and consistent ride.


  1. Best for cold weather
  2. Stable and smooth
  3. Versatile heat-range
  4. Durable and long-lasting


  1. Not compatible with all type
  2. Might leak oil while pouring

5.9 Cummins Oil Capacity and Oil Viscosity Chart

To get the best of the recommended oil for 5.9 Cummins diesel, you have to make sure that you are maintaining the oil viscosity. For that, you need to keep an eye on the temperature range so that the ash content remains at 1.85%. Now, here are the oil viscosities in a tabular form.

12-Valve 5.9L Cummins (1989-1998)

Ambient TemperatureOil Viscosity
Greater than  10° FSAE 15W-40
From 0 to 10° FSAE 10W-30
Less than 0° F (with heater)SAE 10W-30
Less than 0° F (without heater)SAE 5W-30

24-Valve 5.9L Cummins ISB (1999-2002)

Ambient TemperatureOil Viscosity
Greater than  10° FSAE 15W-40
From 10 to 30° FSAE 10W-30
0 or Less than 0° F (with heater)SAE 10W-30
Less than 0° F (without heater)SAE 5W-30

 24-Valve 5.9L Cummins ISB (Common Rail, 2003-2007)

Ambient TemperatureOil Viscosity
Greater than 0° FSAE 15W-40
All temperaturesSAE 5W-40 (synthetic)

How to Choose the Right Motor Oil for 5.9 Cummins?

There is no doubt that all of the products have excellent features and specialties. However, there are still a few things that you need to keep in mind before making a decision. So, take a close look at the following aspects.

Accurate fitment

That is probably the most important factor in choosing accurate engine oil. Even if you happen to purchase the best oil in the market, it will be useless if it does not match with the fitment of your engine.

So, before doing anything else, check your manual thoroughly and sort out the ones that match the fitment. After that, select anyone you like from that short-list. Thus, you can get the perfect fitment.

Micron size

Macron size determines how well your oil can work against contaminants or build-ups. And so, if you get an oil that has a micron level of 10 or more, you can get up to 95% filtration.

Thus, it can promote the efficiency of your oil and keep all the engine parts safe as well. So, keep that in mind and opt for oil with a higher micron level.

Correct viscosity

Every engine oil is not compatible with all heat ranges. Depending on the fitment and the temperature, you need to match the correct viscosity value for your engine.

A technique to do that is to check a synthetic oil weight chart with the recommended viscosity values. After that, go through the specifications of the engine oil thoroughly and match the best one.

Dirt control

Now, dirt control is another key-factor of engine oil. You see, when you start running your engines, all sorts of dirt-particles tend to build upon it. As a result, your oil gets clumpy, and you need to change it again.

However, if your engine oil has superior dirt control, it can deal with all those build-ups by itself. Thus, it can also improve the changing interval of your oil.

Ash content

Ash contents of engine oil can promote build-ups and decrease the efficiency of the engine drastically. That is why the oil never exceeds the limit of 1.85% of the total mass. Therefore, check the ash content before making any decision.


We have got a detailed vision of each of the products. Now, let us clear out some of our doubts with the FAQ section below.

Question: Do I Need to Add Oil Additives?

Answer: You might use oil additives as they work great for enhancing the performance of your engine. Also, it adds to the protection measures and elongates the lifespan as well.

Question: How much oil does a 5.9 24 valve Cummins take?

Answer: Well, the regular capacity of a 5.9 Cummins is around 12 quarts. However, you get 1-quart oil added to it. So, you can add up to 11 quarts of oil.


Your 5.9 Cummins never disappointed you. Then, how can you let it down by choosing a bad engine oil for it? That is why ensuring nothing but the best oil for 5.9 Cummins should be your top priority from now on.

Of course, you can choose any of these outstanding products. However, I would still recommend you to go for the Castrol Edge Oil for the best performance. Nonetheless, prioritize your thoughts and go for the one that you like best.

We will be happy to hear your thoughts

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