How to Determine When to Change Car Engine Oil?
2 Answers
Methods to determine when to change car engine oil include the smell test, the rubbing test, the color test, and the light test. Below are detailed explanations of these methods: Smell Test: Pull out the dipstick and smell the oil. If there is a strong sour odor, it indicates the oil has deteriorated and should be changed. Rubbing Test: Take out some old oil and rub it repeatedly between your thumb and forefinger. Good-quality oil will feel smooth, produce little residue, and have no friction. If you feel impurities, poor viscosity, or even a gritty sensation, it's time to change the oil. Color Test: Place a few drops of old oil on a clean white filter paper. After the oil seeps in, good-quality oil will leave no powder, feel dry and smooth to the touch, and show a clear yellow stain. If the oil appears dark brown or black with visible impurities, it should be changed. Light Test: Hold the dipstick at a 45-degree angle and observe the oil droplets under light. Good oil will show no visible particles. If there are many particles, the oil should be changed.
I drive frequently, so regular oil checks are crucial. Pull out the dipstick to check the color and viscosity: fresh oil is usually light yellow and transparent. If it turns black, thick, or contains impurities, it’s time for a change. Wipe the dipstick with a tissue—if the residue is black, it indicates aging. Also, listen to the engine: if unusual noises increase, acceleration feels sluggish, or fuel consumption rises, it may signal insufficient lubrication. Driving habits matter a lot—frequent highway or congested driving can deplete oil faster. Keep track of the last oil change mileage; typically, change every 5,000 to 10,000 kilometers. Don’t wait for the warning light—timely maintenance can extend engine life by over a decade and save fuel and costs. I always change it myself—simple and practical.
