How to Determine Whether Car Engine Oil Should Be Changed
3 Answers
The methods to determine whether car engine oil needs to be changed are as follows: 1. Prepare a blank test paper, then take out the used oil from the car engine and drop it onto the blank oil paper. 2. Observe the changes of the oil on the test paper. If the oil shows stratification, divided into three layers in total: the outermost layer is the diffusion layer, the middle layer is the oil ring, and the innermost black substance is the oil deposit, then the car's oil needs to be changed. 3. If the oil dropped on the test paper shows unclear stratification, with only two layers and no obvious black deposits in the middle, then the car oil can still be used. 4. Generally, new oil will not stratify, and when dropped on the test paper, it appears very clear and bright, proving that the purchased oil is brand new and unused.
To determine if your car's engine oil needs changing, my experience suggests focusing on mileage and oil condition. Generally, change it every 5,000 to 10,000 kilometers, but specifics vary by model—check the manual or ask a mechanic. Pull out the dipstick to check the oil level; it should be between the high and low marks. Fresh oil is golden-yellow, but if it turns dark black, it's time for a change. If oil dripped on paper spreads quickly with spots, it indicates high contamination and degradation. Driving habits also matter: frequent short trips or traffic jams accelerate oil oxidation, possibly requiring a check every three months. Don’t ignore odd smells—clean oil is fresh, while a burnt odor is a warning. Timely oil changes protect the engine, reduce wear, and prevent bigger losses. Also, ensure proper disposal of used oil to avoid pollution.
As a car owner who frequently checks my vehicle, I prefer to test the oil quality myself. Pull out the dipstick, wipe it clean, reinsert it once, and observe the color change: new oil is bright golden and transparent, while old oil turns dark brown like coffee grounds and must be changed. Dip a finger in the oil and rub it to check viscosity—if it's too thin and slippery, it indicates severe degradation. Odor is also a clue—neutral is fine, but a pungent smell signals trouble. Mileage isn't a strict rule; since I mostly drive in the city, I check every 5,000 kilometers. Pair this with regular filter changes, and don’t let the oil exceed one year. This approach saves worry and money, protects the engine, extends component life, and reduces noise. Remember, regular maintenance is an investment, not an expense.
