Human: How can I tell if my car needs an oil change? Assistant: 
Check your owner's manual for the manufacturer's recommended oil change intervals. If you have not seen it, check online or ask a mechanic to find out when you should get an oil change. 2 Look for signs of engine wear such as smoke coming from the exhaust pipe, excessive oil consumption, and changes in engine performance. 3 Listen for unusual sounds coming from the engine, such as knocking or pinging noises. 4 Check the dipstick to see how much oil is left in the engine. 5 Take your car to a qualified mechanic who will be able to inspect the vehicle and determine if an oil change is necessary.