What does it mean for a car to idle?

[McAdriana]

Car idling refers to the condition where the engine and wheels are in a power transmission state, the throttle is closed, and air enters the engine through the throttle gap and the idle adjustment bypass channel, meaning the car moves without pressing the accelerator. After ignition, the car enters the idling phase. If the car is running without pressing the accelerator, and the engine speed remains at the idling stage, it is idling. In the idling state, the engine only needs to overcome its internal friction resistance, with no other load, and does not output power externally. It is one of the basic operating conditions of the engine. It provides convenience for car owners in various driving and temporary parking situations, such as preventing the engine from stalling while waiting at a red light, while also contributing to energy saving and emission reduction.

[Brooke]

Idling in a car refers to the vehicle slowly moving forward while the engine is still running, such as when you're inching forward in stop-and-go traffic or coasting without turning off the engine while waiting. I believe this is the state where the engine operates at its lowest RPM, typically maintaining around 800 to 1000 revolutions per minute, with fuel being injected but not completely burned. Idling most commonly occurs in long queues at traffic lights or when searching for a parking spot—you press the brake to stop, release it to move, and this cycle repeats endlessly. The issue is that it not only burns fuel inefficiently, consuming over 20% more than normal driving, but also easily leads to carbon buildup, increasing engine strain. It's advisable to avoid this situation whenever possible; if waiting for an extended period, just turn off the engine. In fact, many newer car models come with auto start-stop systems specifically designed to address this, saving fuel and being more environmentally friendly, though it may feel less smooth initially and require some getting used to. Developing good habits is crucial—don't let your engine keep humming away pointlessly.

[BrielleLynn]

I often encounter idling while driving, which basically means crawling forward without turning off the engine in city traffic jams. Imagine being stuck in the middle of a queue during morning rush hour, with slow traffic light changes—you press the brake, stop for a few seconds, then release it and inch forward slowly. That’s typical idling driving. The engine runs at low RPM, around 1,000 on the tachometer. It’s actually quite annoying—fuel consumption noticeably increases. I’ve calculated that frequent short-distance idling can add an extra 1-2 liters per 100 kilometers. The noise is also significant, and, more importantly, increased emissions worsen air pollution. Doing it occasionally is fine, but long-term idling can damage the engine, wearing out piston seals and other components faster. To reduce this, the most practical solution is planning routes in advance to avoid congestion or trying manual stop-and-go driving. In short, keep idling under a minute for safety and cost-efficiency.

[AveryAnn]

Idling in a car refers to the vehicle moving while the engine is running at low speed without load, such as when queuing for a parking spot or inching forward at a traffic light. This significantly increases exhaust emissions, causing environmental pollution, with carbon monoxide and hydrocarbon levels multiplying. I recommend minimizing such operations to save energy and reduce emissions. Utilizing auto start-stop functions or turning off the engine promptly can effectively improve the situation.