Differences Between Gasoline Engine Oil and Diesel Engine Oil
2 Answers
Here are the differences between gasoline engine oil and diesel engine oil: 1. Different fuel economy grades: According to the ACEA European Lubricant Classification Standard, the latest classification consists of 3 series. The A/B series are for gasoline and light-duty diesel engine oils. The C series is for catalyst-compatible engine oils. The E series is for heavy-duty diesel engine oils. 2. Different compression ratios: The compression ratio of diesel engines is more than twice that of gasoline engines, and their main components are subjected to much higher temperatures, pressures, and impacts than gasoline engines. Therefore, the materials used for some components differ. 3. Different sulfur content: Diesel fuel has a higher sulfur content than gasoline. This harmful substance forms sulfuric or sulfurous acid during combustion, which, along with high-temperature and high-pressure exhaust gases, enters the oil pan, accelerating the oxidation and deterioration of the engine oil. Hence, diesel engine oil formulations require more antioxidants and additives to maintain a stronger alkaline state.
I've handled many cases of owners mixing up engine oils. The difference between gasoline and diesel engine oils is significant! Diesel engine oil has stronger anti-corrosion properties because diesel combustion produces more acidic substances. The viscosity grades are completely different too. For example, common CK-4 diesel oils contain more anti-wear additives specifically designed for diesel engines' high compression ratio working environment. The biggest issue is that the two types of oil have fundamentally different formulations. Random mixing can lead to sludge buildup and clogging. Just last week, I dealt with a diesel pickup that had gasoline engine oil in it - the engine sounded like a tractor. For daily maintenance, always follow the API specifications marked in the owner's manual, and never cut corners by using the wrong oil.
