Under what circumstances does a car idle?

[CarolineDella]

When waiting at a red light, the car is stationary and the accelerator pedal is not pressed, at which point the engine operates at idle. Here is relevant information: Idling operation: Idling occurs when the engine and wheels are in a power transmission state, the throttle valve is closed, and air enters the engine through the throttle valve gap and the idle speed adjustment bypass channel. Prolonged idling can easily lead to carbon deposits: During idling, the car operates in a rich fuel injection state, meaning the throttle opening is very small, and the fuel injector sprays a high concentration of fuel to ensure engine operation. Therefore, idling itself is more likely to cause carbon buildup compared to driving at normal or high speeds. Extended periods of idling will definitely result in more severe engine carbon deposits.

[OOmar]

When driving, I often encounter idling situations. The most common scenario is waiting in line at a red light intersection, where the car is stationary but the engine is still running. Especially during rush hour traffic jams, crawling at a snail's pace in the flow of vehicles also counts as idling. Additionally, brief stops such as picking up or dropping off friends, waiting at a gas station to refuel, or warming up the engine for a few minutes during cold winter starts to raise the engine temperature all qualify. I remember one time when I went to the supermarket to buy groceries and temporarily parked by the roadside to load goods, I also used idling. I think idling consumes a lot of fuel, so I try to minimize the time spent, such as turning off the engine at long red lights to save some fuel. For safety, remember to engage the handbrake during idling to prevent the car from rolling. These scenarios are all part of daily life, and with more experience, you'll know how to handle them.

[McMaximus]

As a parent driving kids around, there are quite a few idling moments, like waiting in line at the school gate for children to come out, with the car parked and engine running, turning on AC for warmth in hot weather. The same goes for brief stops when shuttling between extracurricular activities, or slowly cruising the neighborhood looking for parking spots. Safety comes first - make sure to properly engage gears during idling to avoid accidental gas pedal presses causing accidents. I also pay attention to keeping windows tightly closed so kids don't get chilled. However, idling wastes fuel and pollutes the air, prolonged exposure may affect children's health, so it's recommended to limit it to absolutely necessary moments only.

[DeMarcus]

When I first started learning to drive, I noticed frequent idling. Whether stopping at red lights or waiting for green lights, the car wouldn't move but the engine kept running. Crawling in traffic jams also counts as idling, as do short daily stops like waiting for a friend to come downstairs by the roadside. The key to saving fuel, as my instructor said, is that idling consumes a lot of gas—turn off the engine whenever possible. I've tried shifting to neutral to save some fuel and reduce idling. Simply put, it's when the car is stationary or moving extremely slowly while the engine continues to operate. Less idling is better for both your wallet and the environment.

[SanStephanie]

Driving into the city for work every day, idling is the norm. During rush hour traffic jams, you can only inch forward bit by bit, and waiting at red lights that take longer to turn green also involves idling. When I stop briefly at a convenience store to buy coffee, I don’t turn off the engine, or when I take a call while parked momentarily. Modern cars come with automatic start-stop features to help save fuel, but in some road conditions like steep slopes, idling is still necessary. Avoid prolonged idling to save gasoline.

[MaxLynn]

Having driven cars with advanced systems, the idle situation has changed. For example, during brief stops at red lights, the auto start-stop feature shuts off the engine to save fuel, but maintaining cabin temperature with the heater or air conditioning still requires idling. In daily traffic jams when moving slowly, the engine keeps running, and the same applies during brief stops to drop off passengers. After learning about idle fuel consumption, I manually turn off the engine when unnecessary idling exceeds one minute, which is both eco-friendly and economical.