The original engine oil specification for the Volkswagen Golf is 5W-40. This vehicle requires SN-grade or higher engine oil, with a replacement volume of 5L under normal usage conditions. Recommended international brands include Shell, Castrol, and Mobil; domestic brands include Great Wall, Tongyi, and Kunlun. 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, ensuring smoother cold starts for the vehicle. The second number represents the kinematic viscosity of the oil at 100°C. A higher value indicates better maintenance of viscosity under high temperatures, which can also be understood as better lubrication performance under high-temperature conditions. The method for changing the engine oil in a Golf 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 it stops flowing. 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 engine oil to the oil seal of the new oil filter and tighten it clockwise by hand. Add new engine oil through the oil filler cap on the engine valve cover, typically filling three-quarters of a standard oil container. Start the engine and let it run for 5 minutes, checking for oil leaks around the drain plug and oil filter. If leaks are found, repairs should be made. After stopping the engine, pull out the oil dipstick to check that the engine oil level is within the standard range.
