Does Using the Heater While Idling Consume Fuel?

[OGemma]

Using the heater while idling does not consume fuel. The difference between heating and cooling: Theoretically, using the heater does not consume fuel because the car's heating and cooling systems operate differently. When cooling, the air conditioning compressor system engages, increasing the engine's load. Continuous use of the compressor will inevitably raise the engine's fuel consumption. In contrast, the heater utilizes the heat from the engine's coolant to warm up the air, which is then circulated to a small radiator. When the blower operates, it directs this warm air into the cabin, placing a relatively small load on the engine. How to use the heater: When using the heater, make sure not to press the AC button, as this will activate the cooling system. Since automatic air conditioning systems adjust accordingly, doing so can slow down the warming process and increase fuel consumption.