If you do not regularly exchange the air filter, what effects does this have on the engine?

You answered correctly by selecting all three effects. If the air filter is not changed regularly, it can become clogged. This restricts the airflow to the engine. Restricted airflow means the engine may not get enough oxygen, which leads to incomplete combustion. As a result, fuel consumption increases, engine power decreases, and the percentage of harmful substances (like carbon monoxide or hydrocarbons) in the exhaust gases goes up. Regular air filter replacement helps keep your engine efficient and environmentally friendly.