How much fuel does an engine consume at idle speed?
3 Answers
Based on the current general vehicle displacement of 1.5-1.8 liters, the fuel consumption at idle speed is approximately 1-2 liters per hour. If the air conditioning is also running, the gasoline consumption during idle will be even higher. Generally, gasoline engines idle at around 800 RPM, while diesel engines idle at about 500 RPM. The higher the vehicle's displacement, the more fuel it consumes per hour at idle. Below are the impacts of vehicle idling: 1. Consumption: Fuel consumption. 2. Carbon buildup: The engine will accumulate carbon deposits. Prolonged idling can lead to excessive carbon buildup, causing insufficient power during driving and, in severe cases, black smoke from the exhaust pipe.
As a driver with over ten years of experience, I often encounter engine idling situations, such as during traffic jams or while waiting for someone. The specific fuel consumption during idling varies from person to person, but generally, it can consume 0.5 to 1.0 liters of fuel per hour, depending on the engine size, temperature, and the vehicle's age. For example, my family car has a 1.6-liter engine, and idling for half an hour can burn nearly half a liter of fuel, which adds up to tens of dollars wasted each month. It's best to avoid prolonged idling, especially with the air conditioning on in summer, as it consumes even more fuel. Planning your trips wisely can save a significant amount. Developing the habit of turning off the engine if you're parked for more than a minute not only protects the engine but also extends the lifespan of its components.
From an environmental perspective, I have always been concerned about idling issues. It may seem trivial, but it wastes a significant amount of resources. The average idling fuel consumption is around 0.7 liters per hour. Calculating just ten minutes of idling per day, it amounts to dozens of liters of gasoline wasted annually—neither cost-effective nor environmentally friendly. I measured with a dashcam and found that carbon emissions multiply several times during idling. I recommend using public transport or shared mobility more often. Breaking the idling habit, such as switching to remote start for preheating the car, can reduce environmental impact while saving fuel.
