What does CH-4 15W-40 mean?
1 Answers
CF-4 is the quality grade of automotive engine oil; 15W-40 is the viscosity grade of automotive engine oil. 1. Quality grades of automotive engine oil: Diesel engine oils (represented by "C") are classified as: CC, CD, CE, CF, CF-4, CH-4, CI-4, etc. 2. Viscosity grades of automotive engine oil: Multi-grade oils include 5W-50, 10W-30, 15W-40, etc., which have all-season performance. The larger the difference between the numbers before and after W, the wider the applicable temperature range. Additional relevant information is as follows: 1. To ensure the lubrication effect of the engine, the engine oil must have appropriate viscosity and good viscosity-temperature characteristics, so that the viscosity is less affected by temperature changes. If the viscosity of the lubricating oil is too high, it will increase the movement resistance between friction pairs, making cold starts difficult, reducing mechanical efficiency, and increasing fuel consumption. If the viscosity is too low, it cannot form a strong oil film between friction pairs, resulting in poor friction reduction and increasing engine wear. 2. Generally, engines that frequently operate under high-load conditions, are old, severely worn, have large clearances between parts, or operate at high temperatures should use engine oil with higher viscosity. Conversely, engines should use oil with lower viscosity.
