How long can a car be parked without turning off the engine?
2 Answers
Leaving the car running continuously for several days is fine (provided there's enough fuel). Here are some related points: 1. Increased fuel consumption: If the engine remains on for over an hour while parked, fuel consumption will rise. Even though the car isn't moving, fuel is still being used. Although the RPM may stay below 1000, fuel consumption persists, typically increasing by 5%--10% depending on the vehicle. This explains why fuel consumption is higher in traffic jams compared to normal driving. 2. Idle protection: Forgetting to turn off the engine and idling for over an hour won't harm the car; modern vehicles are quite robust, and many now come equipped with idle protection features.
I often encounter situations where I need to temporarily park my car. The two biggest concerns when leaving the engine running are the rapid increase in fuel consumption and aggravated engine carbon buildup. One winter, I waited for 40 minutes with the engine on and the heater running while picking up my child, and the displayed fuel consumption soared to 3 liters per hour, equivalent to driving 20 kilometers. A mechanic mentioned that idling for over 30 minutes tends to make the air-fuel mixture too rich, doubling the rate of carbon deposits. Safety is even more critical—if exhaust fumes seep into the car in a semi-enclosed space like a parking lot, carbon monoxide can become fatal within minutes. During summer, when waiting with the air conditioning on, I usually limit it to under 20 minutes. If the wait is longer, it's safer to turn off the engine and step out of the car.
