
Here are the differences between CH oil and CI oil: 1. Different grades: The first letter of diesel engine oil is "C", and the grades are CA, CB, CC, CD, CE, CF, CF-4, CG-4, CH-4, CI-4, CJ-4. Each subsequent letter represents a higher quality grade of oil. In other words, the CI grade is higher than the CH grade. 2. Different performance: With each increase in the oil quality grade letter, the performance is superior to the previous one. Whether it is the stability of the oil (detergency and dispersancy) or the protection performance for the internal engine (anti-corrosion and anti-oxidation), CI grade oil is better.

I've been running an auto repair shop for twenty years, dealing with engine oil every day. CH oil is mainly used for older diesel vehicles made before 2002, and it handles basic emission standards just fine. CI oil, on the other hand, was introduced after 2004 and is specifically designed for modern diesel engines with complex exhaust gas recirculation systems, offering better soot control and reduced deposits. The key difference is that CI contains more advanced anti-wear additives to prevent carbon buildup. Using the wrong type—like CI in an old car—might work, but if you use CH in a newer model by mistake, the engine warning light could come on. I always advise car owners to check their vehicle manual and not skimp on oil to save a few bucks, only to end up spending big on engine repairs. Using the right oil during regular maintenance can significantly extend engine life.

As a veteran truck owner since '06, I've used all kinds of engine oils. CH oil works fine for older vehicles, but after switching to CI, I noticed the engine runs quieter and the exhaust isn't as pungent. CH was designed for early 2000s engines, while CI is optimized for newer machines with improved detergent formulas to handle soot issues. For daily use, CH is worry-free in older trucks, whereas CI offers extra quietness and eco-friendliness. But don't upgrade blindly unless your vehicle was made post-2004. Once I mistakenly used CH in my '05 truck and nearly needed repairs – luckily I caught it early and switched back. Choosing the right oil protects your engine; don't invite trouble by cutting corners.

When learning to drive, my friend told me that choosing the wrong engine oil can damage the car. Both CH and CI are diesel engine oil standards. CH is suitable for older models, such as those before 2002; CI is newer and designed for engines with emission systems after 2004. CI oil has additional additives to prevent soot clogging, making the engine run smoother. Beginners should not confuse them—checking the vehicle's year is the most reliable method. Using CI in older cars is possible but not particularly meaningful. I've tried both and didn't notice a huge difference; the key is to match the vehicle's requirements.

I always drive with environmental protection in mind. CH engine oil is designed for older diesel vehicles, serving as the foundation for emission control; CI is superior, working in tandem with modern engine exhaust systems to reduce pollution, especially excelling in soot management. The key difference is that CI can support stricter emission standards, thereby protecting the environment. It's advisable for new car owners to switch to CI to contribute to cleaner air. Older vehicles don't necessarily need to upgrade to CI, but selecting the appropriate grade during maintenance can extend their lifespan. Don't overlook this—using improper engine oil affects exhaust quality, and in the long run, it makes the planet dirtier.


