Is it okay to not change the engine oil for seven months in a car?

[AndersonRose]

It is acceptable for a car to go without an oil change for seven months. Engine oil, also known as motor lubricant, is composed of base oil and additives. The base oil is the primary component of the lubricant, determining its fundamental properties, while additives compensate for and improve any deficiencies in the base oil's performance. Engine oil is categorized into full synthetic, semi-synthetic, and mineral oils. The functions of engine oil include: 1. Neutralizing acidic substances produced by combustion gases to prevent engine rust and corrosion; 2. Preventing pollutants and oxide impurities generated during combustion from adhering to the engine's interior, maintaining cleanliness; 3. Reducing friction and damage between moving parts; 4. Absorbing heat generated in the engine's combustion chamber and piston tops to cool the engine; 5. Filling the space between piston rings and cylinder liners to prevent combustion pressure leakage.

[DelaneyAnn]

Last time I delayed changing the oil for eight months, and the engine noise became noticeably louder. When I took it for inspection, the technician said the oil had thinned out like water. Engine oil typically has a shelf life of six months to a year, but in actual use, it deteriorates due to high-temperature oxidation, gasoline dilution, and moisture absorption. Seven months is indeed pushing the limit. Especially in northern winters with longer warm-up times or frequent short trips, oil degradation accelerates even faster. My rule of thumb now is to change the oil whichever comes first—time or mileage. Full synthetic oil can stretch to a year at most, but conventional mineral oil should never exceed six months. If you're still delaying the change, I suggest checking the oil's viscosity with the dipstick immediately. If it lacks that slick, oily feel when rubbed between your fingers, it's definitely time for a change.

[Cassandra]

Having worked in car repair for over a decade, I've seen too many cases of forgotten oil changes. Expired engine oil is like overnight tea—it may look drinkable but has already gone bad. If left unchanged for seven months, metal debris accumulates into sludge inside the engine, causing the most damage to camshafts and crankshafts. Last week, I repaired a Lavida whose owner hadn't changed the oil for nine months—the drained oil was black as asphalt, and half a bowl of sludge was cleaned from the oil pan. There's a reason maintenance cycles specify six months: oil additives like detergents and antioxidants are mostly depleted by then. Even if you've only driven 3,000 kilometers in seven months, the oil still needs changing.

[SawyerAnn]

I remember my brother's old Camry suffered a major loss due to prolonged overdue oil changes leading to an engine overhaul. Engine oil endures temperatures over a hundred degrees Celsius daily, with its protective properties sharply declining after six months. Exceeding seven months doubles the risks: first, the oil film thins, accelerating cylinder wall wear; second, sludge buildup in the oil pan clogs oil passages; most critically, acidic compounds corrode bearing shells. Many owners delay action as long as the car runs, only realizing the severity when the oil light flashes or fuel consumption spikes—often too late. Turbocharged vehicles are especially vulnerable, as turbo bearings rely on oil for cooling—degraded oil can cause bearing seizure. Immediate oil change is advised—don’t wait for the engine to protest.