Does Starting a Car Consume Fuel?

[StReese]

Starting a car consumes fuel. Introduction to fuel consumption: Even when the car is stationary after starting, it still consumes fuel. When the car is parked but the engine is still running, it maintains a low rotational speed to prevent stalling, known as idling. During this time, the engine continues to consume fuel, albeit in smaller amounts. In other words, as long as the car is started and the engine is running, it will consume fuel. Engine carbon buildup: When a car is idling, the fuel does not burn completely, which is the main cause of engine carbon buildup. Engine carbon buildup increases the car's energy consumption and reduces the engine's power output. Additionally, the harmful substances emitted in the exhaust gas during idling are 73 times higher than those emitted when the car is traveling at 80 km/h.

[Kyle]

Starting the car definitely uses some fuel, but not as much as you might think. I previously checked with the onboard computer, and the fuel injection during a cold start is slightly higher to help the engine warm up quickly, but this only lasts a few seconds. The real fuel consumption occurs during the warm-up phase after starting, especially in winter, which can last one or two minutes—during this time, fuel consumption can be up to 50% higher than normal. So, I recommend not idling for too long; just drive slowly after about half a minute of starting. This protects the engine and saves fuel. Also, short trips are the worst—the car barely warms up before you arrive, pushing the average fuel consumption up to over 10 liters per 100 km.

[DelCaroline]

It's certain that a small amount of fuel is consumed every time you turn the key to start the engine, as a cold start requires extra fuel injection for ignition. However, the actual fuel consumption is minimal—measured to be around 0.002 liters per start, equivalent to just a few drops. The real issue arises with frequent short-distance trips, like starting the car in the morning to drop kids off at school before the engine fully warms up, which naturally keeps fuel consumption high. A practical suggestion is to combine short trips into one outing or simply walk for distances under three kilometers.

[IvanLynn]

Starting the engine consumes slightly more fuel than idling, as it needs to overcome the resistance of the engine at rest. However, the key factor isn't the startup itself but the engine warm-up process afterward. Before the temperature gauge reaches 90°C, the engine will inject extra fuel, especially in winter when using the heater slows down the warming process. I once started the car at -10°C and drove immediately, and the fuel consumption reached 20L/100km in the first five minutes. If you only drive three or four kilometers before shutting off the engine, it's like wasting fuel just to warm up the car.