Diesel Engine Oil Vs Gasoline Engine Oil | What Are the Actual Differences?

When purchasing a new car, you must consider several serious factors. The most confusing matter is to choose diesel engine oil or gasoline engine oil. Both of these oils are popular and used widely on cars. So, what are the differences between diesel engine oil and gasoline engine oil?

Though they are widely used in the car, they have some visible differences. For example, you will discover viscosity, additives level, replacement intervals, and catalytic converter & emissions differences. These differences allow you to choose the right oil for your car.

Diesel Engine Oil Vs Gasoline Engine Oil

Diesel Engine Oil Vs Gasoline Engine Oil

Before exploring the differences between these two oils, let’s know them briefly so you can get a clear concept. In a basic sense, gas and diesel engine oil have similar operations. Both oils are used to turn the fuel into mechanical energy and help the vehicle move forward.

Though their operation is similar, these engine oils have some core differences. You will undoubtedly make the right choice after reading the following differences.

What differences Between Diesel Engine Oil & Gasoline Engine Oil?

Based on the lubricant needed performance for each type of vehicle’s engines, we have to make proper differences.

1. The Viscosity

When you think about oils for your vehicle, viscosity first comes to mind. Viscosity is one of the essential lubricant elements in the oil. A higher viscosity provides higher performance on the oil.

However, diesel oils have higher viscosity and lower temperature benefits. Similarly, gasoline engine oil comes with lower viscosity than diesel engine oil. Unlike lower temperatures, gas produces heat, wear, and tear and also creates other problems.

Check: Viscosity Modifiers

2. The Additive Levels

Like viscosity, the additive is also an essential element of engine oil. Different engines have different levels per volume and, of course, come with different components. That’s why they demand different additives levels.

If we need to compare these two engine oils for additives level, undoubtedly, diesel comes with more additives than gasoline engine oil. Diesel engine oil is ready to take more pressure than gasoline because of more additives.

3. The Replacement Intervals

In the oil industry, plenty of oils have, and every oil has a different lifespan. However, diesel oils have more additives which make the oil last longer than gasoline oil. On the other hand, you don’t need to change the diesel oil frequently when you use the oil for your vehicle.

4. The Catalytic Converter & Emissions

What is a catalytic converter?

It is a component in the exhaust system positioned between the muffler and the engine. The main job of this component is to transform the engine’s harmful emissions.

Based on the catalytic converter of the engine oils, your vehicle engine gets better performance from diesel engine oil. Diesel engine oil comes with a higher anti-wear level, providing better transformation of harmful things. Note it is not recommended to use diesel engine oil on the gasoline engine oil.

Check: Can I Use Diesel Oil in Gas Engine

A Comparison Chart Between Diesel Engine Oil & Gasoline Engine Oil

Diesel Engine OilGasoline Engine Oil
Diesel engine oil is more powerful engine oil than gasoline engine oilGasoline engine oil is also ready to provide enough power but not more than diesel oil
Diesel oil has more viscosity to provide higher performanceGasoline oil comes with less viscosity than diesel oil. And it provides less performance than diesel oil.
Protect the vehicle engines from wear, tear, rust, and other harmful things.It also protects the engine from rust, wear, tear, and other things, unlike diesel oil.
Mostly Diesel oils are Mineral type and not too much costly.Generally, Synthetic blends or fully Synthetic Gasoline engine oils are popular and these are high in price.
Some Examples: 15W40,20W50 Example: 5W30

Check: Mineral Engine Oil Vs Synthetic

Can I Use Diesel Oil Safely in My Gasoline Engine?

Most recently, API (American Petroleum Institute) released two new categories: C and S. C for diesel oil and S for gasoline engine oil. The majority of oil experts believe that it should be avoidable to mix diesel oil and gasoline oil because of engine damage problems.

But, when your gasoline or diesel oil comes with these categories C and S, I can safely say that you can mix these two oils without any problems.

Note you have to remember that your oil has to come with these two categories. If anyone is missing, you have to avoid mixing or using diesel oil safely in your gasoline engine oil.

15w40 Diesel Oil in Petrol Engine

15w40 diesel oil is designed for passenger cars and lightweight commercial vehicles. It is compatible with a petrol engine. Moreover, you can consider this oil system for LPG or dual-fuel engines without getting any errors.

This diesel oil protects the petrol engine from wear, tear, and so on. Undoubtedly, it is ready to increase the engine lifespan and provides solid performance.

Diesel Engine Oil Vs Gasoline Engine Oil

FAQs (Frequently Ask Questions)

Q: Will diesel engine oil damage a petrol engine?

Answer: Diesel engine oil is not hurt your petrol engine oil. Even diesel engine oil protects the engine from wear, tear, rust, and other harmful things. On the other hand, diesel oils have high viscosity, which is also compatible with a petrol engine.

Q: Can I use regular oil in a diesel engine?

Answer: The answer is no. Because many additives need for antifoaming, on the other hand, a regular gas engine doesn’t need additives like a diesel engine. Similarly, regular and diesel oils also have viscosity differences, which means regular oil is not ready to provide better performance on the diesel engine.

Q: Can you put 10w30 diesel oil in a gas engine?

Answer: Yes, you can put 10w30 diesel oil in a gas engine. But, you should maintain some principles before putting 10w30 diesel oil in a gas engine. However, you must check that the oil comes under the S or C category. When you find out both of these categories, you can easily put 10w30 diesel oil in a gas engine.

Wrapping Up!

Undoubtedly, these two oils are popular among vehicle owners. You can also mix them when the oils come under S and C categories. However, diesel oils have more viscosity and additives than gasoline engine oil. So, you will get more benefits from diesel oils without any doubts.

In addition, both oil operations are similar, and their goals are the same. But their ingredients and features are different. Overall, most automobile experts suggest using diesel oil to get better performance.


Emon is Lubricants specialist who studied on Petroleum Engineering in UAE. He have more than 10 years experience on different kinds of lubrication including automobile troubleshooting.