Oil Myths: Does Black Oil Mean Change It?

Oil is the car’s blood, lubricating every moving part, reducing friction and wear and keeping the engine running. Used wrongly, it causes faults of its own. Which myths should you discard?

1. Thinner or thicker is better

Owners split into two camps. In fact neither is right: viscosity is not a measure of quality. Too low and lubrication suffers; too high and the engine works harder. Viscosity is also seasonal: thinner oil for winter, thicker for summer, following the grade the manufacturer specifies.

2. More oil is better

Some owners overfill to be safe. Overfilling loads the engine, and surplus oil can reach the combustion chamber and burn. Fill to between the marks on the dipstick.

3. Black oil must be changed

Dark colour means the dispersants are holding soot in suspension, which is exactly their job. Judge by mileage and time, not colour.