The original oil specification for Cadillac XTS is 5W30. 0W40 oil is also acceptable for Cadillac XTS, but the choice mainly depends on the actual conditions of the vehicle, such as the driving environment and the owner's driving habits. Generally, 5W can be used in most regions during winter, while 0W is recommended for some northern areas (e.g., Harbin). 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 latter number represents the kinematic viscosity of the oil at 100°C. A higher value indicates better viscosity retention at high temperatures, which can also be understood as better lubrication performance under high-temperature conditions. The method for changing the oil in Cadillac XTS is as follows: Wait for the engine temperature to drop, allowing the oil to flow back into the oil pan; Loosen the oil drain plug with a wrench and use an oil pan to collect the old oil until no more oil flows out. Start the engine for about 30 seconds to allow the oil in the main oil passage to drain; Remove the oil filter using a specialized wrench; Apply oil to the seal of the new oil filter and tighten it clockwise by hand; Add new oil through the filler cap on the engine valve cover, usually filling up to three-quarters of the oil container; Start the engine and let it run for 5 minutes, then check for any oil leaks around the drain plug and oil filter. If leaks are found, perform necessary repairs; After stopping the engine, pull out the oil dipstick to ensure the oil level is within the standard range.
