Best 15w40 Diesel Oil - Car of Steel

Best 15w40 Diesel Oil

Best 15w40 Diesel Oil

The diesel engine needs a high viscosity oil that combusts at a much higher compression ratio than gasoline. The 15W-40 diesel oil is suitable for the most newer diesel engines because it is heavier and thicker than other standard oils.

It is vital to change the oil on a diesel engine regularly. In addition to regular oil changes, make a huge difference in reliability, performance, and fuel consumption.

The heavy-duty diesel oil will protect your diesel engine from heat, cold, wear, and sludge. It provides both protection and lubrication at the same time. It also works perfectly well in any State.

If you want to keep your engine at peak condition, it is the right place. Here in our guide, we will discuss some 15w40 diesel oil currently available on the market that keeps your diesel working and clean without a hiccup or any damages.

Product Review Session:

1. Royal Purple 04154 15W40 Oil One Gallon- Best oil for high mileage cars that burn oil

Royal Purple 04154 15W40 Oil One Gallon- Best oil for high mileage cars that burn oil

The Royal Purple 15W40 oil diesel works both on diesel and gasoline engines. This diesel oil is one of the easiest ways to enhance engine performance.

These engine fuel grades for a diesel engine that is compatible with synthetic and conventional motor oils. Its high film strength is 2 to 3 times stronger than other full synthetic oil.

Diesel engine oil 15w40 includes ethanol-based fuel. The 15w40 synthetic diesel oil prevents metal-to-metal contact, owing to the proprietary additive technology. It provides superior cleaning and leaves a protective film against wear and corrosion.

This particular oil works on high mileage and a solid performer when it comes to wot truck engine performance.

It prevents white sludge and lubrication starvation that you commonly get with higher ethanol fuel sources. This is the best synthetic engine oil for diesel engines.

Key Features

· Item Weight: 7.7 pounds


· Enhanced additive technology

· Compatible with mineral and other synthetic oils

· Patented ZDDP additive

· Capacity 1 gallon

· No rust oil

· Improved compatibility with fuels containing ethanol


· Enhanced corrosion protection

· Optimize engine performance

· provide superior protection

· Better wear protection

· Dropped the engine temperature even when carrying heavy loads

· API licensed motor oil

· Reduces sludge formation


· not enough for two oil changes for a diesel truck.

· It does not fix bad bearings.

2. Shell Rotella T4 Triple Protection Conventional 15W-40 Diesel Engine Oil- Best oil for high mileage diesel engine

Shell Rotella T4 Triple Protection Conventional 15W-40 Diesel Engine Oil- Best oil for high mileage diesel engine

The Shell Rotella T4 diesel engine oil protects from viscosity loss. This 15w40 synthetic diesel oil Rotella loaded Triple Protection Technology to keep up with the ever-changing driving condition and engine requirements.

This particular model has an acid control system that ensures the engine stays protected from acids. The 6.7 Cummins synthetic oil also offers deposit control, enabling the motor to remain clean and run optimally for a long time.

The wear control ensures that the moving metal surfaces stay apart, which adds to the engine’s life.

It is suitable to use on-highway fleets, construction, pickup trucks, high-power vehicles, and other engines. Its specifications have gained approval from many leading motor and engine companies.

This heavy-duty diesel engine oil provides a 30% decrease in ash, which protects against sludge and deposits.

It gives all-around protection for both turbo and non-turbo engines. This is the best oil for turbo diesel engines.

Key Features

· best diesel oil for the power stroke

· Enhanced shear stability performance for viscosity control


· Protects the motor from acid corrosion

· Heavy-duty diesel engine oil

· Advanced additive technology

· Improved protection deposits and sludge

· Suitable for a wide range of heavy-duty diesel-engine applications


· best motor oil for high mileage engines

· Keeps the engine clean

· Enhanced oil aeration

· Protect against viscosity loss

· API approved, exceptional wear protection

· Reasonable price

· Cleaner filter and engine throughout the oil drain interval

· Recommended oil for Cummins diesel engines


· Not suitable for motorcycles

3. Mobil 1 112786 15W-40 Delvac Super Motor Oil- Best oil filter for Duramax diesel engines

Mobil 1 112786 15W-40 Delvac Super Motor Oil- Best oil filter for Duramax diesel engines

Mobil Delvac 1300 Super offers excellent shear stability as well. This is highly resistant to viscosity changes based on temperature to protect your vehicle well in almost any scenario. It gives you better motor efficiency compare to other diesel oils.

This particular model comes with Mobil Oil’s for Duramax and delivers exceptional performance in all Duramax engines for both old and new. It offers 50 percent more wear protection and outstanding oxidation stability.

The Mobil Delvac diesel oil gives you enhanced TBN reserves, which improves corrosion protection and extends drain intervals. It provides stay-in-grade shear stability and delivers excellent performance in low-temperature.

This 6.6 Duramax oil type super motor oil delivers excellent soot and viscosity control, meeting all API CK-4 requirements. It works perfectly for both older and naturally aspirated conventional designs. This heavy-duty trucking oil provides off-highway performance for trucks providing mining, construction, and agricultural applications.

Key Features


· Item Weight: 7.5 pounds

· Includes Soot-viscosity control

· Can be used in marine applications

· Made from mineral base stocks

· Offers Shear, Thermal and Oxidation stability

· Enhanced TBN reserves

· OEMs and latest API gasoline service category


· Corrosion protection

· Added energy efficiency

· Keeps the engine running efficiently

· Reduction of engine deposits

· Reasonable price tag

· best diesel oil for Duramax


· It only comes in quart containers

4. Genuine Ford Fluid XO-15W40-5QSD SAE 15W-40 Super Duty Diesel Motor Oil- Best synthetic oil for Ford 6.7 diesel

Genuine Ford Fluid XO-15W40-5QSD SAE 15W-40 Super Duty Diesel Motor Oil- Best synthetic oil for Ford 6.7 diesel

Genuine Ford Fluid diesel motor oil includes Additive technology that works to enhance the performance of the engine. The Ford approved oil for 6.7 power stroke.

This engine oil does not void the warranty requirements of Ford Motor Company and most of the other engine manufacturers. It is currently available at a reasonable price.

This diesel oil offers great soot-viscosity control, which allows the engine to perform efficiently and serve your car’s needs for a long time. It also prevents the buildup of deposits and sludge, which can interfere with an engine’s performance.

This super-duty diesel motor oil protects the engine from corrosion, and it increases drain intervals for engines.

Key Features

· ASIN: B000NU9C24

· Item Weight: 9.4 pounds

· Premium hydro-processed base oils

· Compatible with Ford Motor Company requirements

· Additive technology

· 6.0 power stroke oil viscosity


· Doesn’t void Ford Motor Company warranties

· Works for power shift applications

· Suitable for an old engine

· Affordable price tag

· Stable performance

· Best oil for Ford diesel

· Ford recommended oil for a 6.0 power stroke.


· It comes in quart containers.

5. Lucas Oil 10076-PK4 15W-40 Magnum High TBN Truck Oil

Lucas Oil 10076-PK4 15W-40 Magnum High TBN Truck Oil

The Lucas Oil 15W-40 lubricant, Lucas Magnum CJ-4, is an ideal option for both new and old vehicles. This is a synthetic blend oil that boasts a low-smoke formula. It is specially designed to prevent carbon deposits to the piston rings, skirt, crown, and under crown areas. It is a suitable oil for regular use.

This particular model is tested after 30,000 miles of use and meets industry specifications. It protects your motor as well as cleans your engine for a long time. It holds lots of soot in suspension compare to other standard oils.

It works great with low pressure and enhanced drain intervals and leads to improves engine life with no dry starts. It is safe to use a 6.7 power stroke.

Key Features

· Pack of 4

· Item Weight: 33.3 pounds


· Additive package

· Lasts longer than standard 15W-40 oils

· SAE viscosity of rating 15

· Usable in pre-2007 trucks

· Suitable for use with two-stroke engines

· Prediluted for mixing at all temperatures


· Low operating temperatures

· Enhanced oil aeration

· Improves drain intervals

· Resists thermal breakdown

· Suitable for lawn equipment

· keep your motor protected


· no cons yet

Things to consider before purchasing 15W40 diesel oil:

Cleaning capability

It is a critical term. You should consider a diesel oil that effectively cleans your engine and leaves it running smoothly.

Driving conditions

Highway miles are less taxing on a diesel engine, compared to city miles. It offers fewer stops and a more even engine load. The internal pressure of this engine oil is always under even pressure.

The city miles are considered much more taxing. It takes a long time for the vehicle’s engine to reach the operating temperature. It is suitable for uneven load and varying temperatures, which negatively affect the longevity of the engine.

The diesel engine has enough pressure to remove soot particles that cling to the DPF filter when the car is idling. So you should choose a motor oil that is specially designed for prolonged idling times and severe operating conditions.


The viscosity of the diesel engine varies with the range of the ambient temperature. You should check the owner’s manual of your vehicle for a viscosity chart. This will enable you to decide on the starting temperature of the engine. It offers optimal performance even when working under pressure.


The engine oil protects against metal-to-metal contact. It would be best if you considered paying attention to the API classification, and you must check the owner’s manual for the correct API classification required for your engine.

You should also consider the capability, versatility, Manufacturer Specifications, Engine mileage, and efficiency levels.

Frequently Asked Questions (FAQs):

Can I use regular oil in a diesel engine?

Yes, diesel oil is suitable for daily use in a diesel engine. It provides additional protection against motor wear and tear. Most of the diesel motors recommend changing the oil every 5,000 miles. You should follow your manufacturer’s recommended.


The diesel engine oil increases fuel efficiency, reduces wear, and dissolves sludge. It is suitable to use farm equipment, semi-trucks, pickup trucks, and autos.

We think Shell Rotella T4 Triple Protection Conventional 15W-40 Diesel Engine Oil is the best diesel oil currently available on the market. We like it because it is the best oil, Cummins. This is the right choice for heavy-duty vehicles.

It provides long-lasting performance and reliability. It keeps your engine clean and protects against the viscosity loss.