What is the most fuel-efficient temperature setting for car air conditioning?

[CollinMarie]

Turn the air control knob to a higher setting initially. For example, when first entering the car, set it to level 4, then reduce to level 2 after the temperature drops, enhancing convection to cool down faster. As for the temperature adjustment knob, avoid setting it too low to minimize the working time of the refrigeration compressor, which naturally reduces fuel consumption significantly. The reasons for unpleasant odors in car air conditioning are as follows: 1. Accumulation of dust in the indoor filter and internal copper components: After prolonged use, dust accumulates in the indoor filter and internal copper parts of the air conditioning system. When this dust reaches a certain level, it produces odors that disperse into the air when the air conditioning is turned on. 2. Moisture inside the indoor unit: After cooling or heating, the indoor unit often retains moisture. If the air conditioning is turned off immediately without a drying or anti-mold function, this moisture remains, leading to mold growth over time and the consequent production of musty odors.