Is There a Problem If a Car Hasn't Had Its Oil Changed for a Year and a Half?

[Dave]

It is problematic if a car hasn't had its oil changed for a year and a half, as the oil will deteriorate and lose effectiveness, providing no protection to the engine. The functions of engine oil: Engine oil lubricates and reduces friction, aids in cooling, seals against leaks, prevents rust and corrosion, and acts as a shock absorber for the engine. Regular oil changes are essential: Depending on the type of oil, fully synthetic oil typically needs to be changed every 10,000 kilometers, semi-synthetic oil every 7,500 kilometers, and mineral oil every 5,000 kilometers. Even if the mileage hasn't been reached, the oil must be changed after one year because, even if unused inside the engine, oil loses most of its functionality after a year.