What happens if the engine oil hasn't been changed for a year and a half without reaching the mileage?
2 Answers
Even the best engine oil will deteriorate after one year of use. Even if full synthetic oil hasn't reached the recommended mileage, it still needs to be replaced. The impacts are as follows: Possible insufficient oil volume: The engine continuously consumes oil during operation, although the consumption rate is relatively slow. As long as there is no oil burning, there generally won't be insufficient oil within the normal oil change interval. Accelerated oil aging: Engine oil not only provides lubrication but also has a cooling effect. Although the heat absorbed by the oil is ultimately dissipated through the engine and coolant, insufficient oil volume will definitely reduce the efficiency of circulation and heat dissipation, potentially leading to higher oil temperatures and faster oil aging. Increased engine sludge: Prolonged failure to change the oil will result in reduced oil volume while the engine continues to operate, continuously producing particles. These particles will dissolve in the oil until the oil becomes increasingly thicker.
Not changing the engine oil for a year and a half is dangerous even if you drive less than the recommended mileage. Last time I neglected this, my car wasn't driven much, but the oil oxidized and deteriorated, significantly reducing lubrication. As a result, the engine noise increased, fuel consumption rose, and there was strong hesitation during startup. Inspection revealed accumulated moisture and dust in the oil, causing increased friction and slight cylinder wall wear. The mechanic said engine oil has a shelf life of just six months to a year - exceeding this causes acidification that damages seals. Long-term neglect could lead to engine overheating or internal corrosion, with repair costs easily running into thousands. It's recommended to change oil every six months regardless of mileage - otherwise you'll save small money but spend big. Regular maintenance is the right way to care for your car, extending engine life by years. I've since learned my lesson and set phone reminders - it's worry-free and hassle-free.
