Should Engine Oil Be Changed When the Engine is Hot or Cold?
4 Answers
Actually, engine oil can be changed whether the engine is hot or cold, but relatively speaking, it's better to change the oil when the engine is hot. The timing and precautions for changing engine oil are as follows: Timing for oil change: For a new car under normal driving conditions, if synthetic oil is used, the oil can basically be changed every 10,000 kilometers, and some can even extend to 20,000 kilometers. Precautions for oil change: Engine oil is extremely important for engine operation as it is responsible for both lubrication and heat dissipation. Too much oil will increase the rotational resistance of the crankshaft, reduce the engine's output power, and the excess oil may enter the combustion chamber and participate in combustion, causing the vehicle to burn oil, emit blue smoke, and even increase fuel consumption.
Having worked in the workshop for a long time, I understand that changing the oil when it's warm is best. After the engine runs for a few minutes and is turned off, wait for the temperature to drop to a warm state. At this point, the old oil has better fluidity, allowing for a thorough and complete drain, and the new oil provides better lubrication. Although changing the oil when the engine is cold is safer, the old oil's high viscosity makes it prone to residue, which can affect engine performance. It's recommended to wait 10 minutes after driving before performing the oil change, wear gloves to prevent burns, and avoid high-temperature environments. Regular oil changes extend engine life, and the frequency should be adjusted based on vehicle condition and weather. Before starting, clean the work area and recycle the old oil for environmentally friendly disposal—simple and efficient.
I recently learned how to change engine oil and experienced both hot and cold oil changes. The first time I changed oil on a cold engine felt easy and safe, but later I noticed some sediment from the old oil didn't fully drain. A friend suggested driving for a while to warm up the car before changing, which worked much better. Now I always drive for 10 minutes, let it cool slightly, then proceed – the oil drains completely, saving money and hassle. Be careful not to let it get too hot to avoid burns; gloves and cardboard are essential. In cold weather, cars start harder when cold, so preheating makes the process smoother. For routine maintenance, I check oil levels monthly to ensure the engine runs healthily.
My family car has been in use for over 20 years, and changing the oil focuses on safety and convenience. Warm engine oil changes are preferred as the oil flows quickly and the old oil is thoroughly drained. If the engine is too hot, it's dangerous; waiting for 10 minutes to cool down is best. Changing oil when the engine is cold is also possible, but more residue remains, which is not friendly to older cars. After changing the oil, start the engine for one minute to check the oil level, and change it regularly every 5,000 kilometers to maintain lubrication. Choosing high-quality oil saves money and avoids overheating and freezing.
