How to Determine When to Change Engine Oil in a Car

[LeDerek]

Methods to determine when to change engine oil in a car: 1. Pull out the oil dipstick, drip the oil from the dipstick onto a tissue paper, and observe the color and viscosity of the oil. If the color appears quite black, it's time for a change; 2. Calculate the mileage. Generally, full synthetic oil needs to be changed every 8,000 to 10,000 kilometers, while semi-synthetic oil should be changed every 7,000 to 8,000 kilometers. Engine oil, also known as motor oil or engine lubricant, is a substance enhanced with additives in base oil, mainly containing anti-wear additives, detergents, dispersants, and multi-grade oil viscosity index improvers. Engine oil is used for lubricating internal combustion engines, with its primary functions being to reduce friction and wear of moving parts and to remove sludge and varnish from the engine.

[LeJoseph]

Having driven a taxi for twenty years, the most straightforward method is checking the dipstick. Each time after parking and the engine cools down, pull out the dipstick, wipe it clean, reinsert it, then pull it out again to observe. If the oil color changes from golden to deep black or becomes cloudy, it indicates severe oxidation; if it feels as thin as water with no viscosity or as thick as paste, it's time for a change. Also, pay attention to driving sensations: increased engine noise, sluggish acceleration, or unexplained rise in fuel consumption often signal insufficient protection due to aged oil. If you frequently encounter city traffic jams, the oil deteriorates faster—check every 5,000 kilometers. Neglecting it increases engine friction, potentially leading to bearing failure and doubling repair costs. Regular oil changes are a life-saving investment—don’t skimp on this small expense.

[MacMaria]

When I first started driving, I didn't know whether to change the engine oil or not, but later I learned a simple method. After the engine cools down, pull out the dipstick. The ideal oil level is between the high and low marks; if it's below the low mark, you need to top it up. If the oil looks dark or has impurities like metal shavings, it's definitely time for a change. Remember to check regularly: inspect the oil every two months or around 5,000 km of driving. If the oil warning light comes on, don't delay—head to the garage immediately. The manual usually recommends an oil change interval, typically between 5,000 to 10,000 km, but check more often if road conditions are poor. In summer, high temperatures cause oil to evaporate faster, while in winter, good oil lubrication helps with cold starts. Developing this habit ensures your engine stays durable and fuel-efficient with healthy oil.

[DelCollin]

Judging the need for an oil change relies on detailed testing. When you pull out the dipstick, new oil is transparent yellow, while turning brown-black indicates high-temperature oxidation. Dropping a drop on paper, a large oil ring spread suggests decreased viscosity. If possible, use test strips to check pH levels—if it's acidic, it's time to change. Synthetic oil lasts longer, but conventional oil should ideally be checked every 7,500 km. If blue smoke comes from the exhaust pipe or the engine shakes while driving, the oil may have degraded and leaked into the cylinders. Always replace the oil filter during an oil change to prevent debris blockage. Routine maintenance is cheaper than repairs—keeping the oil clean ensures a long engine life.

[JulietAnn]

Engine oil health is directly related to driving safety, which I always emphasize the importance of regular monitoring. The dipstick check is fundamental: golden and translucent color indicates normal condition, while turning black, milky white, or having bubbles warns of contamination or water mixing. If you detect unusual odors like burning smell during driving or the oil warning light illuminates, stop immediately to verify. From a safety perspective, it's recommended to inspect and replace according to the manual every six months or 8,000 km; engine oil is prone to oxidation and deterioration after long-distance driving. Delaying oil changes increases the risk of engine wear, and in severe cases, may lead to seizure or breakdown on highways. Develop the habit of frequent checks to protect your vehicle and avoid unexpected repairs.

[NoraMarie]

For affordable and efficient oil maintenance of family cars, I check the dipstick monthly to confirm oil level and color. If the level is between the high and low marks and the color is slightly yellow, the oil change can be delayed. However, with frequent city commuting and traffic jams, oil degradation accelerates, so it should be changed every 7,000 km. A money-saving tip is to buy good quality oil and change it yourself; synthetic oil is durable and cost-effective. Pay attention to seasonal changes—in hot summers, oil thins quickly, so check more frequently. Don’t ignore small signs like difficulty starting the engine or increased fuel consumption, as these indicate it’s time for an oil change. Proper daily maintenance ensures a reliable engine, keeping you on time for work and school runs.