The original engine oil is the one used for the Diesel Great Wall Pao, with the oil model being 5W-40. In terms of applicability, the original oil is more suitable for the engine. However, depending on different needs, engine oil can have other benefits, such as noise reduction, fuel efficiency, and improved performance. Therefore, you can also choose oils from brands like Mobil, Shell, and Castrol. The viscosity of engine oil changes with temperature, so special attention should be paid to its performance under both low and high temperatures. For example, in 5W-30, the first number indicates low-temperature fluidity. 5W means it can withstand temperatures as low as -30°C. The smaller this number, the better the low-temperature fluidity, making cold starts smoother for the car. The latter number represents the kinematic viscosity of the oil at 100°C. A higher value means the oil can maintain its viscosity index better under high temperatures, which can also be understood as better lubrication performance under high-temperature conditions. The method for changing the engine oil in the Diesel Great Wall Pao is as follows: Wait for the engine temperature to drop, allowing the oil to flow back into the oil pan. Use a wrench to loosen the oil drain plug and place an oil pan underneath to catch the old oil until no more oil flows out. Start the engine and let it run for 30 seconds to allow the oil in the main oil passage to drain out. Use a specialized wrench to remove the oil filter. Apply oil to the oil seal of the new oil filter and tighten it clockwise by hand. Add the new oil through the engine valve cover filler port, usually filling up to three-quarters of the oil container. Start the engine and let it run for 5 minutes, checking for any leaks around the oil drain plug and oil filter. If leaks are found, repairs should be made. After stopping the engine, pull out the oil dipstick and check that the engine oil level is within the standard range.
