Differences between diesel engine oil and gasoline engine oil

Diesel engines operate under high loads and have high thermal efficiency, placing greater demands on the oil. In contrast, gasoline engines operate under lighter loads with more precise component clearances, resulting in significantly different oil requirements compared to diesel engine oils.

The difference between diesel engine oil and gasoline engine oil mainly lies in the viscosity of the oil. It's important to know that diesel engines operate under relatively harsher conditions, requiring stronger oil film strength (on friction pair surfaces). Therefore, diesel engine oil has higher viscosity; otherwise, it cannot ensure proper engine lubrication.

Secondly, there are differences in oil additives. During the combustion process of a diesel engine, sulfuric acid or sulfurous acid can form. If these acids enter the oil pan, they will naturally affect the performance and lifespan of the oil. Therefore, diesel engine oils require more oxidants and anti-corrosion additives.

Gasoline engines are much smaller in size compared to diesel engines, and they generate a large amount of sludge during the combustion process. This places higher demands on the dispersing performance of the lubricating oil, requiring it to break down the sludge into smaller particles and suspend them in the oil, thereby avoiding clogging the oil filter.

Diesel engines are much larger in size than gasoline engines and generate a significant amount of carbon deposits during combustion. This places higher demands on the cleaning performance of lubricating oil to quickly remove these deposits and ensure the normal operation of the diesel engine.

The same volume of diesel engine oil additives contains more than gasoline engine oil.

For large mixed fleets and military fleets that have both gasoline and diesel vehicles, using universal engine oil is a better choice to simplify fuel types and avoid engine failures caused by using the wrong oil.

The lubricating performance of universal engine oil must meet the requirements of both gasoline and diesel engine oils, necessitating careful selection and balance among its formulation components, making the selection of its ingredients much more complex.

Since universal oil requires more additives than regular gasoline and diesel engine oils, its price is also higher. However, universal oil has a larger dosage and a longer oil change interval compared to regular gasoline and diesel engine oils, and its oil consumption is relatively lower.