What is the function of the air filter and why should I keep changing it?
A car's engine combusts fuel to generate power. Since combustion requires oxygen, air is sucked in from the atmosphere and mixed with the fuel.
Often, air carries with it a lot of contaminants, like debris, dust particles, pollen and other pollutants, which can damage the engine.
So the air must be filtered of all these contaminants before it enters the engine. This filtering function is performed by the car air filter.
When such an important part gets clogged, it can ruin the performance of the car. So you need to change it when it is dirty.
Automobile Association of Singapore