Best engine oil for older diesel tractors review 2022

A whole bunch of factors comes into play when it comes to picking up the right engine oil for an old diesel tractor. These old beasts are not similar to modern tractors. Therefore, choosing the right oil viscosity is more than necessary.

Choosing the right engine oil by maintaining the essential viscosity rating might seem a complex process. But when you clearly know to rate engine oil, choosing the right engine oil for your vehicle becomes actually much easier.

In this particular article, we will not only suggest to you some of the best engine oils you can think about using for your older diesel tractors but also will tell you the ways to discern the rating of any engine oil.

If you are interested, let’s get started-

Best engine oil for older diesel tractors

Engine oil rating system

While measuring the rating of engine oil, viscosity is the most popular term that comes again and again.

Viscosity refers to the thickness of the oil. The faster the engine oil travels through the viscometer, the lower the viscosity. On the other hand, the slower the engine oil travels through the viscometer, the higher the viscosity or thickness of the oil.

That means engine oil with a higher viscosity level will be much thicker compared to those oils with a lower viscosity rating.

When choosing an engine oil type, you will notice different types of engine oil like 5W-30, 10W-30, 15W-40, and so on.

The former number (which is 5W, 10W, or 15W) refers to the viscosity level of the oil during winter or cold conditions, whereas the latter number (which is 30 or 40) refers to the viscosity of the oil during warm or 100-degree centigrade temperature.

What oil viscosity you should use according to the temperature?

Here is a little chart that will help you to choose the right oil viscosity according to different temperatures-

Oil type

Suitable temperature

SAE 5W/30

-30° to +20°C/-22° to +68°F

SAE 5W/40

-30° to +40°C/-22° to +104°F

SAE 10W/30

-20° to +40°C/ -4° to +104°F

SAE 15W/40

-10° to +40°C/ 0° to 104°+ F

Best engine oil for older diesel tractors

Old diesel-powered tractors are not similar to modern tractors that require low viscosity oil to run. For cold engines or some other purpose, these old machines may require you to have a rich oil solution to give them some juice to run the distance.

The best oil option for an old tractor with an old engine is always 15W/40. 15W/40 with higher additives and less base oil tends to give the boost that the engine of an old tractor demands.

Therefore, we are here to introduce you to the seven best engine oils you can think about pouring into your old tractor’s oil compartment to get the best experience possible.

1. Shell Rotella T5 Synthetic Blend 15W-40 Diesel Engine Oil

Shell Rotella T5 Synthetic Blend 15W-40 Diesel Engine Oil



Shell Rotella




1 Gallon/3.785 L

Protection against

Wear, deposits, and breakdown/ improves oxidation


Improves low-temperature flow


Ergonomic design handle for easy pouring

User experience (10/10)

Rotella never fails to satisfy the users. If you are looking for blended synthetic oil that will allow your old tractor to get some energy, this one should be the most convenient option available.

We just can’t give this one anything less than a ten.

Features worth discussing

Whatever we are sharing here consists of our personal experience and insights that we have got from a large number of users who already are using this specific oil rather than discussing the manufacturer specifications only.

The thing we love most regarding this oil solution is that this one includes a higher percentage of additives than the base oil. Therefore, the oil creates less friction to produce the optimum lubrication that your engine requires.

We can assure you that once you pour this engine oil into the oil compartment, you will notice drastic differences in the performance. The simplistic but effective oil solution kind of makes your vehicle perform better than before.

Another thing worth mentioning here is that Rotella engine oil tends to deliver better mileage as well. Almost 95% of the users have agreed to the fact that using this engine oil helped them to run longer on the street. 

If you are reading this article, you probably are here for a specific oil solution for your old tractors. We can affirm that Rotella engine oil maintains the exact viscosity level to keep the old engine of your truck running without giving you any sort of inconvenience at all.

If you want better performance, this one is surely a must-have item for your old beast.


  1. The oil is suitable for almost all types of diesel-powered trucks.
  2. The container with an ergonomic handle design will reduce the chance of accidental falls while pouring oil into the compartment. 
  3. This oil can even work better in low temperatures with its better oil flow rating.


Use this one for once, and you will surely agree that this one is the perfect choice for most temperature conditions. Anyway, the price of this oil solution may fluctuate every now and then.

2. Mobil 1 15W-40 Delvac 1300 Super Motor Oil

Mobil 1 15W-40 Delvac 1300 Super Motor Oil



Mobil 1




1 Gallon

Best for

Engine efficiency and longer life


Improved oxidation and thermal controllability


Better low-temperature flow rate, meets OEM standards, better corrosion protection.

User experience (9/10)

Good maintenance is what prolongs the life expectancy of your truck’s engine. And one of the primary sources of maintaining your truck's engine is giving it the essential fluid that would keep the internal properties of the engine in check.

If your truck’s engine runs on diesel, this oil solution might be another alternative to redeem the old and elegant performance.

Features worth discussion

If you are using a 10W-30 oil solution for your old truck and feeling like something is off, consider trying this 15W-40 oil for once.

We believe you will notice great performance differences. Your engine should run way better than previously.

We recommend this oil solution for old trucks because the solution includes zinc-based additives, making it compatible with those old engines. The inclusion of zinc-based additives will help to get higher lubrications without facing fewer wearing issues.

Another reason you may go with this oil solution is that this one comes with a good price range. This one is around $10 dollars cheaper than a similar kind of product. Therefore, this oil solution should bring better value to your budget.

The optimized viscosity level of the oil will also come in handy to ensure optimized protection against corrosion and rust inside of the engine compartment.

Again, the flow rate of this oil is enough balanced to reach the complex part of the engine to get improved engine performance.


  1. The oil will meet the OEM standards of most trucks.
  2. The work will work well in both higher and lower temperatures.
  3. You can expect to get longer engine life once you start using this engine oil.


This is conventional oil rather than synthetic oil. Therefore, it may not serve your purpose if you are looking for a synthetic oil solution for your vehicle.

3. Valvoline Premium Blue Extreme SAE 5W-40 Full Synthetic Diesel Engine Oil

Valvoline Premium Blue Extreme SAE 5W-40 Full Synthetic Diesel Engine Oil







1 gallon


Oxidation resistance

Suitable for

Cold weather


Oxidation resistance

Oil type


User experience (9/10)

If your preference is a synthetic oil with a better flow rate, this one from Valvoline is here to make a good impression. If you are asking how much the users are satisfied regarding this item, we would love to mention that almost 90% of the users have given it a five-star rating.

Such rating should easily say about the quality you will get from this oil solution.

Features worth discussing

If you are living in a pretty cold climate condition, your engine may get cold, preventing it from starting. That is when you will need to think about a convenient oil solution to lubricate all the internal properties of the engine.

At that particular moment, this synthetic engine oil with the SAE rating of 5W-40 should bring forth the most convenient experience possible.

First and foremost, using this engine oil will prevent frequent engine stops when you are living at a freezing temperature.

Again, a safe engine start is a common issue in most cold conditions. We believe using this solution as your engine oil will surely give you the authenticity to enjoy a safe start every time you crank the engine. 

Being synthetic, this one will bring superior protection against rust and corrosion, making your engine much safer than ever before.

This engine oil specifically comes for heavy-duty truck engines with better oxidation resistance capacity. Therefore, using this synthetic oil solution will enhance the life expectancy both for the oil and engine.


  1. You will get longer mileage once you start using this oil.
  2. The oil is better suited for freezing temperature, but you can still use it at room temperature as well.
  3. Your truck will run smoother.


There were simply no complaints regarding the quality of the oil. But people indeed complain about sealing and customer service of this item sometimes.

4. Castrol GTX Diesel 15W-40 CK-4 Motor Oil

Castrol GTX Diesel 15W-40 CK-4 Motor Oil







1 gallon


Heavy-duty four-stroke truck, gasoline and diesel light truck, passenger cars


Exceptional performance in severe condition

Protection against

Anti-wear and anti-oxidant protection

User experience (9.5/10)

There are simply no reasons why you should not love this item.  With detergent-based additives, this oil solution comes here to protect you from any kind of severe conditions. 

We believe 9.5 out of 10 is a good score to justify its overall worth.

Features worth discussing

If you are doing some heavy-duty chores where the engine temperature tends to rise up for heavy loads, this oil from Castrol with its detergent-based additives will ensure that the engine never loses its efficiency.

A great thing about this engine oil is that the percentage of additives is much higher than base oil. Therefore, the engine will face less friction while running. As a result, you will get smoother performance and longer mileage with ease.

The viscosity rating of Castrol engine oil is well optimized. Therefore, no matter how higher the temperature level goes, this one will surely cope with the temperature to keep the engine cool and effective.

From heavy-duty four-stroke engines to lighter trucks’ engines, this oil solution has the potential capacity to fit in most available trucks on and off the road. Besides, you can also think about using this engine oil for passenger cars with different API ratings. The optimized construction makes it compatible with most OEM standards.


  1. You can use this Castrol engine oil in your old truck engine without any doubts at all.
  2. You will face fewer engine problems once you start using this engine.
  3. The high-end thermal capacity will make it effective both at high and room temperature.


Well, the price may vary a little depending on the place from where you purchase this item. Other than that, this one seems to be bringing value to your spending.

5. Kubota 1 Gallon Genuine OEM SAE 15W-40 Engine Oil







1 Gallon

Handle design



High performing additives


Wear, rust, and corrosion

User experience (8.5/10)

You might be wondering why we are suggesting engine oil with only a 15W-40 SAE rating. Well, that is because most of the engine oil recommendation here comes for the old heavy-duty trucks, which require high-performing well with rich additives.

If you want to make the engine of your old truck alive again, this one is another convenient option you can choose to purchase.

Features worth discussing

One thing is pretty straightforward, if you want better performance from your old truck’s engine, the additive used on the oil needs to be high-performing.

This engine oil from Kubota is here to make your engine more performing and capable with highly efficient additives. Therefore, your engine’s life expectancy will improve to a great degree with better performance.

Another great thing about the construction of this engine oil is the use of high VI stocks and shear stable polymer. Using such materials makes this one highly effective for most diesel-powered engines.

It does not matter whether you love to drive your truck on or off the highway, using this engine oil surely makes your truck compatible with almost all road conditions.

If you prefer hauling heavy loads using your truck, enhanced engine temperature might be a common affair. This oil solution with its 15W-40 viscosity level is here to handle almost all thermal conditions. From handling slightly cold temperature to high-end scorching temperature, this one is pretty much capable of making you happy in every weather condition.


  1. Using this engine oil will surely allow you to get longer mileage than usual.
  2. The high-performing additives used on the oil will improve the overall engine performance.
  3. With a better flow rate, this oil will lubricate every essential part of the engine with ease. 


Spending around $40 dollars for a gallon of engine oil might seem a little higher. But the price may vary in different places.

6. Tulux T500 15W40 Classic Diesel Engine Oil







55 gallon




The hydrocracked base oil and multifunctional additives

Protection against

Build-ups, high acid neutralization, corrosion, and rust


Longer life and engine efficiency

User experience (9.5/10)

If you are a single truck user, this much volume may baffle you. This one is for those who require engine oil for professional purposes. With a reasonable price range and higher volume ratio, this one will always be a perfect choice for most professional purposes. 

Features worth discussing

There are actually a couple of benefits you will get once you choose this product from Tulux.

First of all, the formulation process of this oil solution is well proportionate to ensure high-end performance in most weather conditions.

The hydrocracked base oil with a higher viscosity level and overly performing will ensure that the engine gets the required fuel to run the engine with optimum proficiency.

With a viscosity rating of 15W-40, this oil solution is rich enough to make your truck faster and more performing. The foam-based solution will reach every corner of the engine to give it perfect lubrication so that every part of the engine can get high-end protection from rust and corrosion.

A great reason you should consider choosing this engine oil is that this one is pretty much capable of neutralizing the acid materials inside of the engine. As a result, the internal part of the engine will always remain protected from super-sensitive contaminants. 

Even the low-temperature properties of this engine oil can come in handy to prevent a cold engine for a smooth and fast start.


  1. You will be able to use this engine oil in both light-duty and heavy-duty trucks.
  2. Using this engine oil will not deter the engine performance under heavy loads.
  3. The level of base oil and additive is proportionate enough to ensure optimum performance.


What cons should I mention here when a product is this good? Anyway, check the API rating if you are planning to purchase this oil solution for passenger cars.

7. 15W-40 Bobcat High-Performance Gas Diesel Engine Oil







2.5 Gallons

Compatible with

Heavy-duty diesel and gasoline engine

Protection against

Corrosion and abrasive


High and low-temperature performance, oxidation resistance, and better engine performance

User experience (9/10) 

This is our last recommendation for a good quality engine oil from Bobcat, and there is no aberration as well. This 15W-40 viscosity oil is compatible with most heavy-duty diesel and gasoline engines, making it a perfect choice for your old trucks. 

We do not want to introduce you to even a single cheap product.  Therefore, our last recommendation on this list will also get 9 out of 10.

Features worth discussing

Not every engine oil comes with the capacity to retain the viscosity level in high and low temperatures. But this bobcat engine oil is not like the other cheap engine oil.

No matter whether you are carrying larger loads or living in a cold climate region, choosing this engine oil will always give you the best experience possible.

From heavy-duty four-stroke engines to lighter pickup truck engines, this high viscosity oil is compatible with all.

The factor we love most about this engine oil is its response against rust and corrosion. With optimized thickness, this engine oil is pretty much capable of creating a layer against all those sublime rust and corrosion. As a result, your vehicle engine will get better lubrication to have a longer life.

If you have an older truck that is not equipped with modern technologies, you can use this engine oil without any sort of hesitation. The rich additives with proportionate base oil levels will always come in handy to give the engine the same zeal that it used to have.

Finally, the container contains around 2.5 gallons of engine oil, allowing you to use one single container multiple times.


  1. This Bobcat engine oil delivers excellent oil pump ability during the winter season.
  2. The oxidation resistance capacity of the oil is quite satisfactory to secure the engine in any given moments.
  3. The oil will surely minimize the oil consumption of your truck engine.


Although the manufacturer suggests choosing the oil for the correct machines, we believe this engine will work just fine in the case of most old tractors. In terms of quality and performance, this high-performing engine oil does exactly the same things it is here to do.

How to choose the right engine oil for old trucks?

older diesel  engine tractors

These are the five questions that will help you to choose the right engine oil for your older trucks-

  1. Viscosity rating of the oil
  2. Additive well-performing
  3. Types of oil you are using in your vehicle
  4. Oil behaves in different temperatures
  5. Percentage of the base oil and additives in the oil

What is the viscosity rating of the oil?

The first and the most important denominator you need to fix to choose the appropriate engine oil for your old truck is the viscosity rating of the oil.

The viscosity rating dictates the overall thickness of the oil, allowing you to know how the oil will behave in different circumstances.

The viscosity rating essentially defines two different situations. The first one is the behavior of the oil in cold temperature, and the second one is the behavior of the oil in hot temperature.

If you are living in a region where the temperature tends to stay between -10° to +40°C, choosing engine oil with a viscosity rating of 15W-40 should bring the most convenient experience for older trucks.

But if you are using a modern vehicle or truck, do check the manual for choosing the right viscosity engine oil for your vehicle.

We have also added an article on heavy-duty truck tire steps. If you are planning to carry your things on the roof of your truck, consider choosing one from the list.

Is the additive well-performing?

Engine oil is not altogether base oil only. Along with the base oil, there stay additives that allow the base oil to perform better. Therefore, checking how much performing the additive of the oil is enough important simultaneously.

Besides, when it comes to lubricating the engine or creating protection against rust, corrosion, or other harmful chemicals, the additive of the engine oil really plays a crucial role.

Therefore, never miss checking the performance capability of the additive to get the best experience possible.

What types of oil are you using in your vehicle?

When it comes to choosing engine oil, three different types of oil predominantly catch our interest. These are-

  1. Semi-synthetic
  2. Synthetic
  3. And Mineral 

That is where the confusion arises. Which type of engine oil should you choose?

Well, if you are talking about truck engine oil, synthetic and semi-synthetic oils are the preferred types for you, whereas choosing synthetic oil with a higher viscosity rating should bring the most convenient experience.

On the other hand, if you are using a modern vehicle or lighter machines that require a frequent oil change, a mineral oil solution may bring the most convenient experience for you.

Consider checking these paints for heavy equipment to get a convenient experience.

How the oil behaves in different temperatures?

Engine oil delivers different attitudes in different temperature conditions. That is why choosing engine oil according to the behavior of the oil in different weather conditions is more than important.

In colder conditions, engine oil with a moderate viscosity level tends to lose its pump ability. Therefore, engine oil with a higher viscosity level is a convenient option for warmer temperatures. The opposite is true for cold climates.

You may also check this semi-truck GPS if you have a semi-truck.

What is the percentage of the base oil and additives in the oil?

We have already mentioned previously that engine oil consists of two different types of material. There can be three different possibilities.  The percentage of the base oil can be higher, or the percentage of the additive can be higher, or the percentage of the base oil and the additive can be equal.

Oil with a higher percentage of base oil tends to lose pump ability in cold weather.

Oil with an equal level of additive and base oil tends to lose its characteristics in different thermal conditions. 

Perfect oil for your truck engine should have more additives than base oil. Choosing such oil will ensure enough lubrication to keep the engine safe and high-performing.

Besides, the oil property tends to stay stable in both hot and cold temperatures.


What engine oil is best for trucks?

The synthetic oil solution is the best option for most modern-day trucks.

Although you can go away with semi-synthetic oil for lighter trucks, using full-synthetic oil for heavy-duty trucks is always the most ideal option.

What should be the viscosity level of a truck engine?

The Viscosity level of a truck engine should be anywhere between 5W-20 to 15W-40, depending on the region you are living in.

If you are living in an environment where the temperature tends to drop, you should use oil with a low SAE rating.

On the other hand, choose a high-viscosity engine if the temperature in your region tends to be higher or you do heavy-duty y chores with your truck.

Can I use full synthetic oil in my truck engine?

Yes, you can always use full synthetic oil in your truck engine. In reality, using synthetic oil is the best available option for your truck.

What does 15W-40 mean?

15W here refers to the thickness of the oil in winter, whereas 40 refers to the thickness of the oil in 100°C temperature.

Can you put regular oil in a diesel truck?

No, it is never advisable to use regular oil in a diesel truck. Using such oil can deteriorate the engine performance dramatically.

Final summary

Engine oil is one of the most important factors that determine the overall performance of the engine. Therefore, choosing the right engine oil is always an important task to accomplish. If you are using an older truck, consider choosing synthetic oil with a higher viscosity rating to make the engine more performing and capable.

Last Updated on June 17, 2022 by sajjad

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