The suitable oil specification for Corolla is 5W20, while older Corolla models can opt for 5W30 oil which has one grade higher viscosity than 5W20, providing better engine protection. For post-maintenance oil changes, brands like Mobil, Shell, Castrol, and Total can be considered. Oil viscosity changes with temperature variations, so special attention should be paid to its performance under both low and high temperatures. Taking 5W-30 as an example, the first number indicates low-temperature fluidity - 5W means it can withstand -30°C, with smaller numbers representing better cold-flow properties for smoother cold starts. The latter number represents kinematic viscosity at 100°C, where higher values indicate better viscosity retention and lubrication performance under high temperatures. The oil change procedure for Corolla is as follows: Wait for the engine temperature to drop, allowing oil to fully drain back to the oil pan; Loosen the drain plug with a wrench and collect old oil in a container until completely drained. Start the engine for 30 seconds to flush remaining oil from main galleries; Remove the oil filter using a special wrench; Apply oil to the new filter's gasket and hand-tighten it clockwise; Add new oil through the valve cover filler port, typically filling three-quarters of a standard oil container; Run the engine for 5 minutes and check for leaks around the drain plug and filter; After stopping the engine, use the dipstick to verify oil level falls within standard range.
