Is Diesel Engine Oil Suitable For Petrol Engine?

The short answer is yes, diesel oil can be used in a petrol engine as long as the diesel oil fits the engine’s specs and viscosity criteria.

If your petrol engine requires API SN-compliant motor oil, for example, you can safely use a diesel oil of the appropriate viscosity if it fulfils the API SN criteria. A diesel oil isn’t required for most petrol applications, and a premium petrol motor oil is a better choice for both performance and value.

The long and short of it is that some owners of modified petrol-powered vehicles prefer diesel oils to their gasoline counterparts.

Many people believe that diesel oils are more durable and can withstand the extra heat produced by a powerful, turbocharged engine.

Others prefer higher-viscosity lubricants to guard against wear, and finding a 40- or 50-weight diesel oil is sometimes easier than finding a petrol motor oil. Others argue that diesel fuels should have more detergency.

Nyholm: It depends on the diesel oil’s parameters and the original equipment manufacturer’s advice (OEM).

Even in Australia, industry experts regard the American Petroleum Institute (API) as the primary source of information on oil quality, so we can consult their publications on the “C category of specification for diesel oil (currently CK-4)” and the “S category of specification for gasoline motor oil” (currently SN). Both the API CK-4 and SN standards are often seen in today’s diesel engine oils.

Though they’re meant for diesel engines, they can also be utilised in gasoline engines for drivers who prefer to use one oil for all of their vehicles. If all parameters are included on the diesel oil, you may rest certain that it is safe to use in both diesel and fuel applications. If the diesel oil isn’t able to carry the load, “I highly advise against using it in petrol applications (S category).

Because many motorists don’t think about oil, it’s common for them to buy based solely on viscosity. Today, many petrol engines require 5W-30, with more and more requiring 5W-20, implying that those viscosities are commonly available. If you’re looking for a 5W-40 or 15W-40 viscosity, the diesel engine oil aisle is frequently the best place to look.

Others prefer diesel oil because they believe it is a more environmentally friendly option “Heavy-duty product that must outperform gasoline motor oils.

They may have been told that diesel oil contains specific components not found in gasoline motor lubricants, such as stronger detergency additives to deal with the soot produced by diesel engines. Diesel oils are equated to higher protection in their minds.

Nyholm: A number of additives are used in the formulation of diesel and petrol oils to increase wear protection, corrosion resistance, foam resistance, viscosity retention, and other properties. Many of the same additives are employed in both petrol and diesel applications, depending on what we’re asking them to do in the formulation.

There are now additives that are designed to manage combustion by-products, and some of those by-products differ depending on whether you’re burning gasoline or diesel. If you have a petrol engine, you should use an oil with the proper additives to manage the by-products of petrol combustion. If you’re driving a diesel engine, the same rules apply.

Looking for the ideal oil for your vehicle? Our Lookup guide is available to assist you.

Nyholm: Using a diesel oil can be advantageous if your petrol engine has been significantly tuned to produce additional horsepower. To resist the extra stress, upgraded engines are likely to require a greater viscosity. Depending on your engine modifications and lubrication requirements, you can use diesel engine oils or you might wish to consider a racing oil.

Frequently, the engine builder will assist in providing insight into their level of success. Aside from that, it’s preferable to go with a petrol motor oil if you have a standard petrol-powered application.

They’re built for that kind of application and include the components needed to run the engine. Yes, you can use diesel oil in a petrol engine; but, the formula is likely to contain additional components that your petrol engine doesn’t require, thereby costing you more money.

What happens if diesel oil is used in a gasoline engine?

Bob’s Letter: Several of my friends feel that utilising diesel oil in gasoline engines extends the life of the engines. They back this by claiming that diesel oil performs better under harder situations than gasoline oil, such as greater temperatures and longer travels. What is the best oil for my car? Which multigrade oil is ideal for places with high summer temperatures, 10W-40 or 20W-50? Here in Mexico, your piece is well welcomed. M.A.L., M.A.L., M.A.L.,

M.A.L., please accept my heartfelt greetings. According to logic, your friends’ thinking is accurate. Diesel oils must withstand substantially greater engine temperatures, oxidation rates, sulphur deposits, fuel soot, acids, and other deposits and conditions not encountered in typical automotive engines. It stands to reason that utilising diesel oil in a gasoline engine would extend the life of the latter.

Is engine oil for diesel and gasoline engines the same?

Mineral oil is used to make both conventional diesel and petrol, however the exact refining procedures differ. Diesel is easier to refine in theory than gasoline, but it contains more pollutants that must be removed before it can emit at the same levels as gasoline. Diesel contains more energy per litre than petrol, and the combustion process in a vehicle’s engine is more efficient, resulting in improved fuel economy and reduced CO2 emissions when diesel is used.

Is 15w40 suitable for gasoline engines?

Types of Vehicles and Fuels Semi Synthetic 15W-40 is compatible with Petrol/LPG (Dual Fuel), E10, Diesel (without DPF), and most other conventional fuels and can be used in passenger cars, 4WDs, and light commercial vehicles.

What is the difference between 10w30 and 15w40 lubricants?

Because 10W-30 oil is thinner than 15W-40 oil, it has a lower film strength and is more prone to oxidation. To compensate for these flaws, high-quality additives are required in order for a 10W-30 engine oil to protect as well as a 15W-40 and last as long.

Is it possible to use diesel oil in my car?

Yes, diesel oil can be used in a gas engine as long as the diesel oil fits the engine’s specs and viscosity criteria.

If your gas engine requires a 5W-30 motor oil that satisfies the API SN PLUS criteria, for example, you can safely use a diesel oil of the appropriate viscosity that fulfils the API SN PLUS specification.

However, for most gasoline applications, a diesel oil isn’t necessary, and a good gasoline motor oil is a better alternative in terms of performance and cost. Let’s take a closer look at the diesel vs. gasoline dispute.

Is diesel oil superior to ordinary gasoline?

Diesel engine oil contains more additives per litre than gasoline engine oil. Overbase detergent additives are the most common. The primary functions of this addition are to neutralise acids and clean. Diesel engines produce a lot more soot and combustion byproducts than gasoline engines. These find their way into the crankcase due to blow-by, forcing the oil to cope with them.

When this excess additive load is applied to a gasoline engine, the results might be disastrous. The detergent will perform as intended, attempting to clean the cylinder walls. This can wreak havoc on the seal between the rings and the liner, causing compression and efficiency to suffer.

So, how can you tell whether an oil is suitable for gasoline or diesel engines? Look for the API (American Petroleum Institute) doughnut when reading a label. There will be a service designation on the top of this doughnut. For gasoline engines, this designation will begin with a “S (service or spark ignition), whereas for diesel engines, it will begin with a “C (commercial or compression ignition).

Is there a distinction between ordinary oil and diesel oil?

With so many different engine oils to select from, you may be unsure which one is best for your vehicle. We’ll go over the fundamentals of diesel vs. gasoline engine oil, as well as the physics underlying these two separate engine designs and some frequently asked engine oil topics.

What Is Engine Oil?

There are numerous advantages to using engine oil. It creates a protective layer by lubricating the moving metal elements of an engine as it warms up. Oil also keeps your engine from overheating as it gets hotter. As the oil circulates, it uniformly distributes the heat generated by the engine until it is carried away by the cooling system. The oil layer between the parts also reduces the amount of power required by the vehicle to overcome friction, improving fuel efficiency and making your car run more smoothly.

Oil also cleans your engine by removing sludge and catching impurities such as smoke, water, humidity, dirt, and metal particles. Engine oil also prevents rusted and corroded metal surfaces. Sludge buildup can cause increased engine wear and, in extreme circumstances, engine failure if these cleaning steps are not taken.

What Are the Key Differences Between Diesel and Gasoline Engine Oils?

The energy from chemical reactions is converted into power for your car by all engines, although gas and diesel engines do so in different ways. There are a few things to bear in mind:

Emissions and the Catalytic Converter

Spark plugs are used in gas engines to ignite them without the use of compression. Diesel engines work by compressing air in their cylinders until it reaches a temperature high enough to ignite the fuel.

Catalytic converters in gas engines convert hazardous emissions into cleaner byproducts and release them into the atmosphere. Byproducts such as nitrogen oxides, hydrocarbons, and carbon monoxide are created during the combustion process. To lessen harmful emissions, catalytic converters break these gases down into nitrogen, carbon dioxide, and water.

Diesel engines emit a byproduct that is not produced by gasoline engines. The “catalytic converter for diesel engines” is the Diesel Particulate Filter (DPF) and other after-treatment devices, which collect soot from the diesel engine cycle.

Diesel engine oils contain compounds that are designed to work with emission systems. The additives are essential to deal with the harsh environment of a diesel engine, but they are incompatible with gas emission systems. If you use diesel engine oil in a gasoline engine, the catalytic converter may be damaged, and long-term use may lead to failure.


The capacity of a liquid to flow at different temperatures is called viscosity. Oil with a high viscosity acts as a shield between metal parts. Oil has a viscous consistency comparable to molasses at low temperatures, but thins out and flows like water at higher temperatures.

Diesel engines are more difficult on oil than gas engines due to their combustion forces. Shearing is a procedure that reduces the viscosity of oils by breaking them down into smaller molecules. Diesel oil is viscous in general, but smaller weights are necessary in gas engines. To satisfy the weight standards, our Blue Diamond oils are manufactured of pure poly-alpha olefin (PAO) oils that only require a minimal amount of viscosity improvers. This allows for more longevity and performance additives to be added to the oil, which keeps it cleaner for longer and improves economy and horsepower.

Additive Levels

Detergents, dispersants, anti-wear compounds, corrosion inhibitors, antioxidants, and friction modifiers are all found in diesel and gasoline engine oils. Diesel engine oil, on the other hand, has a higher concentration of additives than gasoline engine oil. Detergents and anti-wear chemicals are particularly concentrated in diesel oil.

The additional additives aid in meeting the needs of the larger engine. Diesel engines produce more soot and other combustion byproducts than gasoline engines, which are cleaned up by the additional additives.

On the other hand, extremely large additive loads in fuel oil would jeopardise the vehicle’s performance. When extremely concentrated detergents and dispersants clean the cylinder walls in a gasoline engine, they can disrupt the seal between the liner and the rings, lowering compression and efficiency. They can also harm the catalytic converter and cause the engine to smoke. As a result, gasoline engine oils typically have lower quantities of these additives.

Additives increase the quality of your engine oil when used in the proper amounts. Many engine oils contain important additives, but these can degrade over time. It’s critical to account for additives that may be lost along the route in order to maintain your engine’s oil performing at its best between oil changes.

Friction can cause parts to wear down when your engine’s oil loses lubricity. Anti-wear chemicals restore the oil’s lubricating effect. Specific products, such as the FR3 Friction Reducer, improve the lubricity of your oil.

Cleaning solutions remove the burnt oil residue that accumulates over time. Stiction Eliminator lubricates while also removing built-up. In both gasoline and diesel automobiles, the FR3 and the Stiction Eliminator are safe to use.

Engine oil contains detergents and dispersants that clean the engine, but as these diminish, corrosive acids can build. To avoid this, products like TBN Booster replace these cleaning chemicals, allowing corrosion to be prevented for extended periods of time. Only diesel engines should use the TBN Booster. The sulphur in diesel fuel combines with oxygen during combustion to generate sulfuric acid, which is corrosive to all metals in your engine. This type of combustion is counteracted by the TBN Booster.

Replacement Intervals

If you haven’t changed your oil in a while, you’ll notice a significant difference in engine performance. Adding new oil to your engine on a regular basis will help to prevent irreversible damage and guarantee that your car operates smoothly for a long time. Despite their various variances, both diesel and gasoline engines need oil changes every 5,000-15,000 miles. For more information, consult your vehicle’s owner’s manual.

Are These Products Interchangeable?

Many people wonder whether diesel oil can be used in a gas engine or whether gas oil can be used in a diesel engine. Overall, using diesel oil in diesel engines and gasoline oil in gasoline engines is the optimum practise. Some oils, on the other hand, are designed to work in both diesel and gasoline engines. Always double-check your vehicle’s owner’s manual and the oil bottle label to ensure you’re getting the proper oil.

The American Petroleum Institute (API) has devised a classification system for engine oil:

  • The service symbol will be designated with a “S” if the oil is suitable for gas engines (Service).
  • The emblem will include a “C” if the oil is intended for diesel engines (Commercial).
  • It’s suited for gas engines if the emblem indicates “Resource Conserving.”
  • Both gas and diesel engines may use oils that fulfil the criteria. If this is the case, the symbol’s list of service categories will include a “C” followed by a “S.”

Mixing Diesel and Gas Engine Oil

Generally, you should use oil that is specifically tailored for the car you drive. It’s better to use the same weight if you need to top off your oil with a different type. Most engine oils will work in either engine, albeit they aren’t always optimum. Diesel engines require a viscosity that is greater and different additive amounts than gasoline oils. Diesel oil additives that aren’t suited for the system can clog up gasoline emission systems.

Discover the Hot Shot’s Secret Engine Oil Selection

The type of oil you use in your diesel or gas engine is determined by a variety of factors, including how the engine ignites, warms, and emits its fuel. Keep your vehicle’s engine in top shape with the correct motor oil and additives, no matter what it’s powered by.

Is it possible to use 15W-40 diesel oil in a gasoline engine?

A thicker grade of oil, such as 15w40-50, is typically used in diesel engines. If you drive a petrol automobile with diesel engine oil, there will be no problems; but, if you live in a cold region, problems may develop. Because the heavy oil is quite thick and has settled, there is a lot of wear on the engine when it starts up.

Which engine oil is best for petrol engines?

Castrol is the first product on our list of best engine oils for petrol automobiles in India since it is a fully synthetic engine oil from India’s premier lubricant company. You must have seen Castrol’s “Stop/Start TVC so far. If not, we’ll bring it to you.