What are the effects of not changing car engine oil for a long time?

[StPaige]

Long-term failure to change engine oil can lead to insufficient car power and even engine damage. During engine operation, pistons and cylinders slide relative to each other. If the lubricating power of the oil is insufficient, parts will suffer severe wear. Additionally, if the cooling effect of the engine oil decreases, the engine cannot be cooled in time. Prolonged high temperatures will shorten its service life and even affect the overall performance of the car. After all, the engine is the power source of the car, occupying the position of the car's "heart," so timely oil changes are crucial for engine maintenance. Secondly, engine oil can flush away some impurities on engine parts, such as carbon deposits and sludge, playing a role in cleaning the engine. Moreover, engine oil can form a sealing ring between pistons, preventing external contaminants from entering the engine. Therefore, if the oil is not changed for a long time, impurities and pollutants will accumulate. During circulation, not only will the engine fail to be cleaned, but some impurities may also clog the engine, leading to malfunctions. Finally, the oil change cycle also requires our attention. Generally, two standards should be followed. The first standard is time, and the second is mileage. Typically, manufacturers recommend an oil change cycle of 5,000 kilometers or about half a year. However, this data is not fixed and needs to be adjusted according to specific circumstances. For different car models, adjustments should be made based on the oil change intervals provided in the maintenance manual. If changing the oil improves power, it indicates that the timing and cycle of the oil change are appropriate. In summary, in car maintenance, oil changes are a relatively important task. However, many car owners do not know much about this and may even cause engine damage due to prolonged failure to change the oil.

[PenelopeLee]

As a long-time car enthusiast, not changing the engine oil regularly is practically abusing the engine. Fresh oil provides excellent lubrication, protecting internal engine components. However, over time, the oil turns black, degrades, and its viscosity increases, leading to reduced lubrication performance. This causes increased friction between metal parts, accelerating wear on piston rings and cylinder walls. Even worse, sludge and contaminants accumulate, clogging oil passages and causing cooling system failure, which may result in engine overheating or even seizing. If this happens, repair costs can be shockingly high—often thousands for a major overhaul, or even total engine replacement. Regular oil changes are simple: check every 5,000 km or so to save fuel and extend engine life. Don’t cut corners out of laziness.

[LeHadley]

From a cost-saving perspective, I've learned my lesson the hard way by delaying oil changes thinking the old oil was still usable. Eventually, the engine started making noises, fuel consumption skyrocketed, and performance dropped significantly. By the time I addressed it, bearing wear led to repair costs exceeding thousands. The takeaway: expired oil provides poor lubrication, causing excessive internal engine wear that turns minor issues into major overhauls. Regular oil changes cost just tens to a hundred yuan, but the money 'saved' by postponing is negligible compared to repair bills. Car maintenance requires prudent budgeting—invest in small, regular upkeep rather than gambling with luck.

[DelJaxon]

I've learned a lot about driving safety. Delayed oil changes can leave your car stranded on the road. Dirty old oil loses lubrication, causing increased engine friction, rapid heat buildup, and potential part failures. I once experienced sudden engine shutdown on the highway - thankfully unharmed. The mechanic diagnosed sludge blockage as the cause. Regular oil changes prevent such emergencies.