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Oil & Fluids

The Best Diesel Oil, According to 3,000+ Customer Reviews

Last Updated on Aug 10, 2023 By Paul Lucas

What happens if you put the wrong diesel oil in your car? Does it immediately damage the engine? Well, maybe not straight away but sooner or later it’ll definitely hurt both your engine and your wallet. Naturally, low-quality oils don’t keep the friction and heat in check as efficiently as the good ones.

The increased friction leads to more noise, wear and tear, and heat. Ultimately, your vehicle loses its grace and the issues could even go beyond fixing. That’s why you need the best engine oil out there.

However, even the most famous brands can disappoint you sometimes. So, it’s never easy to figure out which one will work for you. If you’re wondering about which engine oil to go for, you’re in the right place.

Here, we’ll review the five best diesel oils you’ll find on the market. We’ll share our experience with them in detail so you can draw a picture of how they’re going to work for you. Lastly, we’ll add a buying guide to help you find out the best diesel oil.

Our 5 Best Diesel Oil – Detailed Reviews

01 Castrol 03057 GTX MAGNATEC 5W-30 Full Synthetic Motor Oil (Editor’s Pick)

Castrol 03057 GTX MAGNATEC 5W-30 Full Synthetic Motor Oil, Green, 5 Quart

Why It Stands Out to Us

The 03057 GTX Magnatec is one of the best engine oils you’ll ever find. This fully synthetic engine oil from the famous brand Castrol offers you a flawless performance. The manufacturers claim that it runs the engine 4x smoother than its competitors. This shows how much confidence they have in their product. The GTX Magnatec offers excellent lubrication of the engine.

Apart from that, it leaves a protective coat on the engine components for additional protection from any kind of damage. With this motor oil in your vehicle, you’ll be able to travel 5000-6000 miles without having to refuel.

What’s more fascinating is that it doesn’t cost more than the other similar oils despite providing arguably the best performance in the industry. If you’re looking for the best engine oil for your car, our top pick is the one you should go for.

Our Experience With the Castrol GTX 03057 Magnatec

  • The oil came with pretty good packaging and the manual was spot-on. These small gestures and care for the customers make a brand stand out among others. The containers had great quality as well.
  • On average, we changed the oil every 5000 miles and tested the oils every time after refueling. The reports came out to be perfect on every occasion, meaning the oil is more than capable of keeping the engine in good shape.
  • Regarding the lubrication, we were very happy. It managed the friction perfectly and there were no wear and other kinds of damages.
  • Unlike most other engine oils, the 03057 seemed to stick with the critical engine parts even when the engine isn’t running.
  • Castrol engineered the oil to put a protective layer on the engine parts. Not only did this protect the engine during all times, but it also enhanced the longevity of the vehicle.
  • After using the GTX Magnatec in several vehicles, we came to the conclusion that it runs best on petrol engines. However, it performed flawlessly in fuel injection systems, Ford EcoBoost, gasoline engines, and spark-ignited direct injection.
  • The heat management was superb. The oil helped run the engine in cold weather without any issue. Also, it didn’t let the engine overheat. This makes it suitable for long-distance drivers.

What We Didn’t Like

  • We noticed that the GTX Magnatec doesn’t suit some cars like the Chrysler Ms6395.
  • The price fluctuates a lot

What Could Be Improved

  • The oil could be available in other viscosity levels.


  • Viscosity: 5w-30
  • Weight: 9.28lbs
  • Dimensions: 9.61x 4.57x 12.01 inches
  • Certifications: API
  • Available configuration: 2
  • Available Sizes: 6


  • Reduces wear and damages
  • Enhances performance
  • Boosts fuel efficiency
  • Flawless temperature management
  • Fully synthetic
  • Great pricing


  • Only available in two viscosity configurations

02 Castrol 03559 Edge 5W-30 C3 Advanced Full Synthetic Motor Oil, 5 Quart (Best for 6.0 Powerstroke)

Castrol 03559 Edge 5W-30 C3 Advanced Full Synthetic Motor Oil, 5

Why It Stands Out to Us

The Castrol 03559 Edge offers an all-around service in an economic price range. It’s so strong that one square inch of this oil can take 10 tons of pressure. This full synthetic motor lubricates the engine like magic. It reduces friction and eliminates any chances of internal damages. Besides, it’s good with either hot or cold weather.

No matter if you’re driving a BMW or a Toyota, engine health is key to longevity. The Edge will keep your car engine in fresh condition if it’s changed correctly. Besides, you can go 4000-6000 miles easily without having to change the oil. All things considered, the Castrol Edge is a great shout for any car owner.

Our Experience With the Castrol 03559 Edge

  • The packaging quality was just as you’d expect from a brand like Castrol. We found the user manual very informative. It had all the needed instructions and information. Castrol did great in terms of presenting the product to their customers.
  • Fuel consumption was satisfactory and we got around 4000-6000 miles between oil changes. No matter what car you own, you should be okay if you change the oil after that 5000 miles mark. We checked the engine regularly for issues but couldn’t find any during the entire time.
  • The Edge provided fantastic lubrication. We noticed that the engine made slightly less noise and performed flawlessly without any hiccups.
  • It reduced any kind of friction in the engine and ran it smoothly. That was another reason for the engine making less noise than usual.
  • We put this engine oil in some fast cars and were amazed at the result. There was no issue regarding heat and the cars were on their absolute best with the Edge. We also found out that the oil helped to keep 4-cylinder engines in complete tune.
  • The oil seemed lighter, which enabled it to spread nicely and provide great lubrication. It also prevented wear and overheating at the same time. If used properly, the Edge will keep an engine good as new for a long time.

What We Didn’t Like

  • Though it kept the engine neat and clean, the oil looked dirty while refueling
  • The fuel consumption was far from the best we’ve seen.

What Could Be Improved

  • The time between the oil changes could be reduced a little.


  • Viscosity: 5w-30
  • Vehicle Type: Car
  • Available Configurations: 4
  • Certifications: BMW Longlife 01


  • Anti-wear technology
  • Boosts engine performance
  • Can handle tons of pressure
  • Manages temperature perfectly
  • Economic


  • Looks dirty when replaced
  • Fuel consumption could improve

03 Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil – 1-Gallon, Case of 3 (Best for 7.3 Powerstroke)

Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil - 1-Gallon, Case of 3

Why It Stands Out to Us

The Shell Rotella T6 boosts the engine’s performance by a huge margin. This full synthetic diesel oil enhances the oil consumption and longevity of your vehicle. With exceptional lubricating features, it reduces friction in the engine and keeps the temperature in check. No matter if it’s hot or cold out there, the T6 will keep your car engine buttery smooth.

Also, the oil prevents the engine from getting any kind of blockage and keeps it neat and clean. Overall, it’s a great product that doesn’t fall too heavy on the wallet as well. So, the next time you’re looking for diesel oil, make sure to look for the Shell Rotella T6.

Our Experience With the Shell Rotella T6

  • The product came with fantastic packaging. The containers of every size were very well thought and designed. It’s always nice to see manufacturers paying attention to the packaging as well.
  • After using the oil for a very short period, we started noticing that the interval between the refueling increased by a lot. We did the math and found out that it saved us about 3-4% money regarding fuel costs compared to the other oils we were using.
  • The engine showed no issues whatsoever while the Shell Rotella T6 was in action. From our experience, we can tell that this oil has exceptional lubricating features that prevented any harmful wear in the engine.
  • We hardly saw the engine overheat. The T6 showed amazing heat resistance that can challenge almost any other product on the market. Besides, it performed very nicely in cold weather as well.
  • We were impressed by the oil’s capacity to work with emission systems. Shell Rotella formulated the oil to be low-ash for controlling the poisoning or blocking in the exhaust after-treatment systems.
  • The T6 performed great in bike engines as well. It enhanced the oil consumption of the bike and also the engine was in great shape throughout the time.

What We Didn’t Like

  • They didn’t seem much suitable for geared motors because they require thicker oils compared to the T6.
  • Some users have complained about the availability of this oil.

What Could Be Improved

  • The oil could be a little thicker


  • Package-Type: Jug
  • Vehicle Type: Car
  • Viscosity: 5w-40
  • Available Quantities: 4
  • Certifications: API


  • Suits gasoline engines perfectly
  • Superior viscosity
  • Great pricing
  • Multi-grade engine oil
  • API certified


  • Not thick enough for geared engines

04 Valvoline Premium Blue Extreme SAE 5W-40 Full Synthetic Diesel Engine Oil 1 GA, Case of 3 (Best for Heavy-Duty Engines)

Valvoline Premium Blue Extreme SAE 5W-40 Full Synthetic Diesel Engine Oil 1 GA, Case of 3

Why It Stands Out to Us

The Valvoline Premium Extreme is one of the best performance-based full-synthetic engine oils. It’s specially engineered for heavy-duty trucks and other powerful vehicles. This oil is famous among the users for its exceptional heat management. Other engine oils may fail you in extremely cold weather but not this one.

What’s more, it features superior wear protection that protects the toughest of engines from internal damages. This might not be the cheapest option available but it’ll most assuredly save you a few bucks by enhancing the longevity of your truck. If you own a truck or industrial generator that features a heavy-duty engine, the Valvoline Premium Extreme is definitely the one to go for.

Our Experience With the Valvoline Premium Blue Extreme

  • The oil arrived with great packaging and a spot-on user manual. We were impressed with how detailed the guide was. There was every bit of information you’d need for using the oil.
  • The engine performed flawlessly with the Valvoline Premium Extreme. It had amazing lubricating features, which kept the engine safe from any kind of internal damages.
  • In terms of heat management, the performance was outstanding. We didn’t face any overheating issues during long drives and performance was exceptional in cold weather as well.
  • While in extremely low temperatures, we noticed that the engine started faster and more accurately compared to most other engine oils we tested.
  • The interval between changing oil was extended after we started using the Valvoline Premium Extreme. We got more than 9000 miles with every car we put it in. Also, it seemed suitable for a wide range of vehicles.
  • The oil eliminated any chances of blockages. It performed perfectly with emission systems as well. We can confirm that it’s suitable for heavy-duty trucks.
  • We also tested the Valvoline Premium Extreme generators and the results were very satisfying. The refueling interval was shortened by a great margin and the engine sounded better.

What We Didn’t Like

  • A bit costly
  • Some users have complained about receiving the oil without the paper seal.

What Could be Better

  • The pricing could be better
  • Could be available in larger quantities


  • Dimensions: 14.5x 9.13x 11.44 inches
  • Viscosity: 5w-40
  • Suitable For: Trucks
  • Package type: Bottle


  • Recommended by Cummins
  • Easy to pour
  • Suitable for cold weather conditions
  • Smooth performance
  • Superior wear protection


  • Expensive

05 Mobil 1 Extended Performance Full Synthetic Motor Oil 5W-30, 5 Quart (Best for Lawn Tractors)

Mobil 1 Extended Performance Full Synthetic Motor Oil 5W-30, 5 Quart

Why It Stands Out to Us

Mobil 1 has been one of the biggest names in the engine oil industry for decades. Millions of people from all over the globe turn to Mobil 1 for the authenticity and performance they offer in their oil.

The Extended Performance is one of the company’s performance-based motor oils. With a full synthetic formula, it keeps your engine clean and sludge-free. The exceptional lubricating features of the oil protect the engine from any kind of internal damage.

No matter if you need motor oil for your car or lawnmower, there are very few in the market that can compete with this performance beast. On top of that, it doesn’t cost you a fortune as well. If performance is your primary concern, this will most assuredly be a solid pick for you.

Our Experience With the Mobil 1 Extended Performance

  • Coming from one of the famous diesel oil manufacturers, this product came with just the kind of packaging you’d expect. We were very hyped to get started with it and it didn’t disappoint us in the long run.
  • In terms of oil consumption, it wasn’t the most efficient diesel oil we used. However, it wasn’t half bad as well. It got us about 1-3% more than most oils we used, which was very impressive in itself.
  • The performance was more of its forte. Ever since we started using it, we noticed a huge boost in the performance and there wasn’t an issue the entire time.
  • Mobil 1 seemed to be spot on with the heat management. We tested the oil in different weather conditions. No matter how hot or cold it was, the engine started accurately every time and there was no overheating issue as well.
  • We were very satisfied with the lubricating abilities. We checked the engines regularly for any wear or damages after extended periods of run time but there were none. It managed friction very well. This also helped in keeping the engine cool for a longer period.
  • It was just as efficient in keeping the engine neat and there weren’t any sludge buildup as well.
  • We tested the Extended Performance on different vehicles and devices for checking its compatibility. It worked fine with every car, generator, and lawnmower we put it in.

What We Didn’t Like

  • The price fluctuates a lot.
  • Some complained the oil made their engines noisier.

What Could Be Improved

  • Fuel consumption could be a little better.

Our Recommendations

  • Make sure to get the Mobil 1 filter for optimum performance.


  • Dimensions: 4.4x 8.1x 12.66 inches
  • Weight: 9.32 pounds
  • Viscosity: 5w-30
  • Available Sizes: 5
  • Certifications: API


  • Excellent performance
  • Outstanding lubrication
  • Exceptional low-temperature capacities
  • Prevents sludge buildup and damage
  • Easily affordable


  • Price fluctuation

Diesel Oil Types

1. Traditional Oil

Being suitable for most cars with a simple engine design, the traditional engine oil is also the most used type on the market. Usually, motorists who own old model vehicles tend to lean towards the traditional motor oil.

2. Synthetic Blends

This type is famous for its duality. The synthetic blends offer the features of both conventional and synthetic oils. With this type, you get the functionalities of the full synthetic oil at a comparatively lower price. These oils perform great in low temperatures and ensure great resistance from oxidation.

Many motorists opt for synthetic blend motor oils as an alternative to full-synthetic engine oils. If you’re one of those who want the maximum performance at a low price point, consider the synthetic blends to be the best choice for you.

3. High Mileage Oil

These oils are specifically engineered for a mileage of 75000 or more. They reduce oil leaks and oil consumption by a great margin. This saves you a lot of money on engine oil. The high mileage oils are also famous for minimizing emissions, heat, and smoke.

4. Full Synthetic Oil

Full synthetic oils are the most advanced form of engine oil. These oils are tailor-made for enhancing the overall performance of the engine. It increases thermal breakdown, oxidation resistance, and viscosity levels and keeps the engine factory clean. Vehicles that require loads of peak performance and lubrication need the quality that these oils offer. With the full synthetic oils, you also get enhanced fuel efficiency and horsepower. These oils are more expensive than the other types. However, it’s a small price to pay for the enhanced performance you get.

Advantages of Diesel Oil

  • Improved Engine Performance
  • Maximize Engine Life
  • Increased Stability
  • Resists Corrosion, Sludge, and Thermal Complications
  • Decreased Evaporation
  • Improved Fuel Mileage
  • Maximize Time Span between Changing Oil
  • Environment Friendly

Best Diesel Oil: Comprehensive Buying guide

Top Diesel Oil - Buying guide

1. Viscosity

Viscosity in engine oils refers to the oil’s ability to work under certain temperatures. Thin oils come with lower viscosity grades, while the thick ones have a greater viscosity grade. Any specific motor oil with a low viscosity level will work great in low temperatures. On the other hand, heavier motor oil will be a way better option for high temperatures.

If the viscosity grade in certain engine oil is 0W20, it can be identified as one of the oils that perform great in both hot and cold weather. In the viscosity grade, ‘W’ represents winter. The numbers on both sides of the ‘W’ denote low and high temperatures. The number on the left side of the ‘W’ indicates how the oil will perform in low temperatures and similarly, the number on the right side represents the performance in high temperatures. As the numbers on each side get smaller, the performance enhances.

2. Additives

  • Antioxidants: Protect the oil from premature degradation.
  • Anti-wear agents: They extend the longevity of the oil by slacking metal degradation.
  • Corrosion and rust indicators: Protects the metal parts of the engine from rust.
  • Detergents: They remove the waste and keep the engine clean.
  • Dispersants: Remove blockages created by dirt and sludge. By doing this, they also enhance the fuel efficiency and performance of the engine.
  • Foam inhibitors: Remove the foam and bubbles to increase the effectiveness and longevity of the motor oil.
  • Friction modifiers: Keep the friction in check to avoid overheating
  • Pour point depressants: Ensure that the wax particles don’t get hardened in low temperatures. This helps the oil flow freely throughout the engine even in extremely cold weather situations.
  • Conditioners: Keep the older engines in perfect shape with conditioned and softened seals.
  • Viscosity index improvers: These additives keep the engine stabilized even when the temperature frequently fluctuates.

3. Application

Synthetic oils perform better than conventional oils and synthetic blends in many ways. They offer greater engine protection, keep your engine clearer, flow better in low temperatures, protect your engine in high temperatures, especially when it’s under high pressure, and lastly, they protect critical turbocharger parts.

4. Quality Certificate

The protection of your vehicle largely depends on the quality of diesel oil you put into it. We recommend that you only go for the products that come with an American Petroleum Institute (API) seal on the packaging. This guarantees that the product meets industry standards set by the ILSAC (International Lubricant Specification Advisory Committee).

5. Compatibility

All diesel engine oils come with two specified descriptions; the performance levels and the viscosity. These two specifications determine if the oil is compatible with a certain engine. Besides, engine manufacturers provide a chart for the recommended viscosity grades it’s compatible with depending on the weather conditions the engine is likely to encounter.

Do a little research on your engine and look into the manual for such information. If the recommended grades and certifications match the specifications of a diesel oil, it’s certain that the oil is compatible with your engine.

6. Adaptability

Diesel oil can be used in multiple ways like lubricating different components of the vehicle. But not all manufacturers make oil that can adapt to different types of applications. That’s why it’s important to choose a product that you can use for different purposes.

7. Cleanliness

Diesel engines need to be kept clean for optimum performance. But you can’t wipe the tank or the engine to keep it spotless. The only way to do so is to use diesel oil that burns clean. Numerous diesel oils on the market don’t burn as clean as you’d like them to. So, for the sake of the longevity of your engine, make sure to go for a product that’s capable of keeping the engine neat and clean.

8. Competence

Everyone knows that diesel is much more economic than the other forms of fuel. However, some diesel oils are more efficient than others with a lower consumption rate that helps prolong the time between drainage. So, for more efficiency, make sure to select your diesel oil wisely.

9. Budget

We’re talking about one of those products that doesn’t have a constant price point. Typically, a jar can cost you from 5 – 20 dollars depending on the brand and functionalities


Q. 1: What are the different types of engine oils?

A: Engine oils can come in different forms such as; diesel oil, lube oil, and gasoline oil. They have different purposes. Normally, diesel oil keeps your engine lubricated and lube oil lubricates the other components of your vehicle. On the other hand, gasoline is somewhat close to diesel in a lot of ways but it’s thinner than diesel.

Q. 2: What are the properties of diesel oil?

A: Any diesel oil contains base oil with a few additive packages like dispersants, detergents, viscosity index improvers, and friction modifiers.

Q. 3: How often should you change the oil in your vehicle?

A: It is best to check your owner’s manual to know how often you should change the oil. While most vehicles’ oil needs to be changed around the 5000 to the 10000-mile range, vehicles that are used for frequent towing may need more frequent oil changes.

Q. 3: What is the shelf life of diesel or motor oil?

A: Depending on the quality,  diesel or motor oil can be stored for up to 5-6 years. However, to get that kind of shelf life, the oil needs to be kept in the conditions guided by the manufacturer.

About the author

Paul Lucas

I grew up in a classic car-oriented family, and was taught how to differentiate between a Ford and a Chevy by my dad when I was just five years old! With special feelings for anything Italian, I enjoy driving and restoring old cars.

Over the years, I became tired of those cookie-cutter auto blogs that copy content from each other and decided to take matters into my own hands! So, I am here to bring you the latest auto industry news, tech innovations, the hottest cars and their specs, reviews, test drives, tuning, and more.

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