Why does automobile air-conditioning waste gasoline?
The more load you put on your engine, the harder it needs to work to run. There are many devices that run off of the engine; the power steering pump, the water pump, the alternator, and the AC compressor are the most typical of these devices. Let’s say you have an engine with no devices attached, running at idle. The engine needs to make only enough power to keep itself turning, and so burns a certain amount of air and gasoline. Now, add on the water pump and other accessories. Some of these accessories make the engine work harder constantly (water pump), while others make the engine work harder when they’re in use (power steering pump, very little load when going straight or turning at speed, but significant load when turning while stopped or at low speed.) As this load increases, the engine needs to put out more power to keep turning at the same speed — and so it needs more air and gasoline. The AC Compressor is a unique device (drive accessory, is the official term) in that it puts
