Can mineral engine oil still be used after seven months?

[LunaLynn]

Mineral engine oil cannot be used after seven months because it deteriorates rapidly after being stored for more than six months, significantly reducing its lubrication effectiveness. Below are detailed explanations: Usage cycles for different types of engine oil: Mineral engine oil needs to be replaced every 5,000 kilometers or six months. Semi-synthetic engine oil has a usage cycle of about 7,500 kilometers or eight months. Fully synthetic engine oil has a usage cycle of about 10,000 kilometers or one year. Hazards of not changing engine oil for a long time: If a car does not change its engine oil for an extended period, the oil will become ineffective and deteriorate. Instead of providing protection, it will increase wear and damage to engine components. Additionally, its cooling effect diminishes, leading to the accumulation of a large amount of carbon deposits and sludge.

[SanHazel]

My previous car also used mineral oil, and after seven months of driving, I felt it was time to check the oil condition. Mineral oil isn’t as durable as synthetic oil—it’s more prone to aging and degradation over time and mileage. At the seven-month mark, I pulled out the dipstick to check the color. If it turned black or the viscosity seemed thin, it was time for a change. Once, my car’s oil had been in use for eight months and was just shy of the 8,000-kilometer limit, but upon inspection, it appeared quite murky. Worried about insufficient lubrication, I promptly changed it. The car ran much smoother afterward. An oil change only costs a few hundred bucks, whereas skimping on it could lead to engine wear costing thousands or even tens of thousands to repair. I’d suggest checking your manual for the recommended interval—most manufacturers advise not exceeding six months for mineral oil, though you can stretch it slightly if you drive less. Regularly inspect the dipstick, and if the oil looks dark or thin, don’t hesitate to change it.

[McColeman]

Using mineral oil for seven full months, I believe it should be judged based on the actual situation. This type of oil has a poor base and shorter lifespan, aging under the dual influence of time and mileage. Seven months is not a short period; the oil may have oxidized and degraded, with viscosity and protective performance declining. Symptoms like louder engine noise, feeling less powerful, or increased fuel consumption could be signs. I have a habit of checking the dipstick every quarter, feeling the viscosity with my fingers—if it's too thin, it's time for a change. If you've only driven around 5,000 kilometers in these seven months, it's not a big issue; but exceeding 8,000 kilometers or long-distance driving significantly increases the risk. Timely oil changes to protect the engine are essential—replacing mineral oil isn't expensive, costing about 200 yuan. Long-term neglect leading to internal engine wear can be costly to repair. Remember, safe driving is paramount, and regular oil checks are key.

[StLevi]

The mineral oil has been in use for seven months, so check it promptly. This type of oil degrades quickly; over time, its performance weakens, and poor lubrication increases engine wear. I've encountered similar situations—when the oil turned black and thin, I replaced it immediately to avoid overheating issues. According to the manual, it's best to change it every six months. While exceeding this period is possible, caution is advised. Oil changes are low-cost but offer high protection—don’t delay.