Does a Car Consume Fuel When Idling After Starting?

[Shawn]

Yes, a car consumes fuel when idling after starting because the internal components of the vehicle are still operating. Below are the impacts of car idling: 1. Prolonged idling can easily lead to carbon buildup: During idling, the car operates in a rich fuel injection state, where the injectors spray highly concentrated fuel to maintain engine operation. As a result, prolonged idling makes the engine more prone to carbon buildup. 2. Wastes engine oil: During idling, the throttle opening is small, and the vacuum inside the intake manifold is high, which can easily draw engine oil vapor into the intake manifold, leading to unnecessary wastage of this portion of engine oil.