What happens if the engine oil in a car is not changed?

[HZoe]

Failure to change the engine oil in a car can lead to oil deterioration, reducing its lubrication effectiveness. When the engine operates, internal components may not receive proper lubrication, resulting in wear and tear on the engine parts. Benefits of changing engine oil: Lubrication and friction reduction: Separates the surfaces of relatively sliding parts. Cooling: Assists the radiator in cooling the engine. Cleaning: Flushes away dirt generated on the working surfaces of parts. Sealing and leakage prevention: Reduces gas leakage and prevents external contaminants from entering. Sealing and rust prevention: Lubricating oil adheres to the surfaces of parts, preventing contact with water, air, acidic substances, and harmful gases. When the pressure at the engine cylinder port rises sharply, suddenly increasing the load on the piston, piston rings, connecting rod, and crankshaft bearings, this load is transmitted through the bearings' lubrication, cushioning the impact load.

[DeElliot]

Let me tell you, as a veteran driver with over a decade of experience, the last time I neglected to change the oil on time, the engine noise was as loud as thunder. When I drove to the repair shop, the oil was black and sludgy. If you don’t change the oil, it gradually gets dirtier and thicker, drastically reducing lubrication effectiveness, accelerating engine part wear, and in severe cases, it can even cause valve seizure or total engine failure. My friend had it worse—once, his engine overheated and burned out, costing him over ten thousand to repair. So, I remind everyone to regularly check the oil condition and not skimp on the small cost. New cars might need an oil change every 5,000 kilometers, while older cars require even more frequent changes. Developing this habit can significantly extend your car’s lifespan and avoid the hassle of breaking down on the road—safety always comes first.

[ArthurMarie]

When working on cars, I often see this situation: if engine oil isn't changed for a long time, it oxidizes and deteriorates, forming gummy deposits known as sludge, which can easily clog oil passages and cause insufficient oil supply. After lubrication fails, engine friction increases, temperatures rise sharply, potentially leading to cylinder scoring or bearing seizure. Moreover, fuel consumption increases and emissions worsen - the gains don't outweigh the losses. I recommend changing the oil every six months or every 5,000 to 10,000 kilometers, depending on what your manual specifies. You can regularly check the oil level and color using the dipstick - if it appears black or has an unusual odor, it's time for a change. Prevention is far more cost-effective than repairs; don't let small issues turn into major problems.

[ArielFitz]

From an environmental perspective, not changing the engine oil not only damages the car but also increases environmental pollution. Insufficient lubrication from old oil causes severe engine wear, leading to more exhaust particulate emissions that pollute the air. I always maintain my car on schedule, saving money and reducing resource waste. Aged oil also reduces fuel efficiency, increasing fuel consumption and expenses. Developing a habit of regular oil changes is simple and protects the environment.