What is the difference between engine oil CH and CI?
2 Answers
The differences between engine oil CH and CI are as follows: 1. CI-4 can meet the usage requirements of China National V engine vehicles, while CH-4 level can only meet the usage requirements of China National III engine vehicles. 2. CH-4, introduced in 1998, is suitable for high-speed four-stroke diesel engines and complies with the 1998 U.S. exhaust emission standards, using fuel with a sulfur content of less than 0.5%. It can replace CD, CF-4, and CG-4 oil grades. CI-4, introduced in 2002, is suitable for high-speed four-stroke diesel engines that comply with the 2004 U.S. exhaust emission standards. For vehicles equipped with an Exhaust Gas Recirculation (EGR) system, CI-4 oil can effectively maintain engine stability and is suitable for use with fuel containing less than 0.5% sulfur. It can replace CD, CE, CF-4, CG-4, and CH-4 oil grades.
Engine oils CH and CI are primarily different specification grades under the API diesel engine oil classification. Having driven trucks for several years, I know that CH-4 is suitable for older engines manufactured between 1998 and 2002, while CI-4 is designed for newer vehicles post-2002, especially those equipped with exhaust gas recirculation (EGR) systems. CI-4 oil can better handle soot and high-temperature oxidation issues, preventing sludge buildup. CI-4 oil is fully compatible with older engines, but the reverse isn't true—using CH-4 in newer vehicles may result in insufficient protection, potentially leading to accelerated wear or malfunctions. I recommend checking your vehicle's manual and manufacturing year during oil changes to select the correct grade, which can save significant repair costs. It's also crucial to regularly check oil levels to avoid major issues caused by prolonged use of the wrong oil. Currently, CI-4 is more widely available in the market, slightly more expensive but worth it.
