What does CJ-4 diesel engine oil represent?
2 Answers
CJ-4 diesel engine oil represents the highest quality grade, where -4 indicates that the oil is suitable for 4-stroke diesel engines. Below are specific details about engine oil: 1. Oil Types: Engine oil grades are categorized into gasoline, diesel, and gasoline-diesel universal types. Oils starting with the letter "S" are for gasoline engines, with specifications including API SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN. Oils starting with the letter "C" are for diesel engines, with specifications including API CA, CB, CC, CD, CE, CF, CF-2, CF-4, CG-4, CH-4, CI-4. If both letters are present, such as SM/CF, it indicates the oil is a gasoline-diesel universal type. 2. Letter Meanings: The further the letter after S or C is in the alphabet, the higher the oil's quality grade, indicating more stable performance and a higher oil grade. Currently, the market also classifies engine oils into three categories: mineral oil, semi-synthetic oil, and synthetic oil. Correspondingly, oil grades from SA to SJ are mineral oils, SJ and SL are semi-synthetic oils, and SM and SN are full synthetic oils. In addition to oil grade identifiers, some oil packaging may feature the SAE label. SAE stands for the Society of Automotive Engineers, which sets standard viscosity values for engine oils, such as 5W-30.
As a heavy-duty truck driver, CJ-4 engine oil is the most common specification for us diesel vehicle owners, especially for vehicles manufactured after 2007. Its biggest feature is the very low ash content, which makes it less likely to clog the DPF particulate filter, and the engine runs quieter and smoother. For long-haul drivers like me who want to maintain their beloved trucks for many years, using CJ-4 can reduce carbon buildup and wear, extending the engine's lifespan. It also has environmental benefits, as new emission regulations require its use. If you accidentally use older specification oil, it might lead to excessive emissions. Don’t be fooled by the packaging when choosing—just look for the API certification mark. It might be a bit more expensive, but it’s worth it. Using high-quality oil during maintenance saves you from repair troubles later.
