How to classify diesel engine oil grades

Diesel engine oil starts with the letter "C" and is categorized into 11 grades, namely CA, CB, CC, CD, CE, CF, CF-4, CG-4, CH-4, CI-4, and CJ-4. As the grade increases by one letter, the performance of the oil improves. When choosing an oil grade, it's best to refer to the specifications listed in the car manual. However, if you frequently drive in congested urban areas, you might consider upgrading to a higher grade of oil for environmental and cost-effectiveness benefits.