
Generally speaking, not changing the engine oil for 20,000 kilometers can cause damage to the car. If the engine oil is not replaced or replenished over a long period of time, it will gradually evaporate due to heat, which may cause the oil to become very thick (like asphalt) and lose its fluidity. This can lead to poor lubrication and heat dissipation, making it highly likely to cause wear on the engine's moving parts or even seizing of the pistons and bearings. Engine oil is categorized into fully synthetic oil, semi-synthetic oil, and mineral oil. These three types of oil differ in quality and have different service intervals. Generally, fully synthetic oil should be replaced within 10,000 kilometers; semi-synthetic oil should be replaced at 7,500 kilometers; and the lowest-grade mineral oil needs to be replaced within 5,000 kilometers. If you notice a sudden increase in engine oil consumption, you should pay attention, as this could be due to increased wear on the piston rings or valve stems. Regardless of the reason, it is important to promptly inspect and address the issue.

I believe that not changing the engine oil for 20,000 kilometers could indeed cause damage to the car. Engine oil functions in the engine like blood, lubricating parts to reduce friction, dissipating heat, and preventing corrosion. If not changed for a long time, impurities accumulate in the oil, viscosity decreases, and lubrication effectiveness significantly drops. This increases internal engine wear, potentially leading to cylinder wall scratches, piston ring damage, or even engine overheating or complete failure. Having driven for many years, I've seen many car owners delay oil changes for convenience, only to end up with louder engine noise, sharply increased fuel consumption, and costly repairs. I recommend regularly checking the oil condition, typically changing it every 5,000 to 10,000 kilometers. If the oil appears black and thick, it should be replaced immediately. Don't save small money at the expense of safety and major losses. Remember, a healthy engine relies on timely maintenance.

I think it's not worth saving money by delaying an oil change until 20,000 kilometers. An oil change only costs a few hundred yuan, but neglecting it will cause the engine oil to degrade and wear out internal components; in the long run, repair costs could amount to tens of thousands. Over time, the oil becomes dirty and loses its lubricating properties, increasing friction and causing the engine to overheat, potentially leading to a breakdown. I experienced a similar issue with my family car—delayed oil changes led to increased fuel consumption, reduced performance, and depreciation when selling the car. I recommend developing the habit of checking the oil according to the maintenance schedule in the vehicle manual and replacing the oil filter promptly. The cost of saving small amounts of money is too high; maintaining your car properly saves more in the long run.

I think it's very dangerous to go 20,000 kilometers without changing the engine oil. The oil deteriorates when overdue and stops functioning, causing severe wear on engine components. I've seen cars break down on the road due to neglected maintenance, turning repairs into a burden. Checking the engine oil should be done frequently, and it should be changed when the color darkens—don't wait until problems arise. Safety comes first, and vehicle maintenance is a must.


