Is There a Difference Between Setting 1 and 4 on a Car's Air Conditioning?

[SanLeonardo]

There is a difference between setting 1 and 4 on a car's air conditioning. The specific differences between setting 1 and 4 on a car's air conditioning are as follows. Fuel consumption: It will increase fuel consumption, but not significantly. This is because the compressor is driven by the engine's belt, and its speed is only related to the engine. However, lowering or raising the setting by one level only changes the speed of the blower fan inside the car. A higher blower speed consumes more electricity, and the car's electricity can only be generated by consuming gasoline. Power: Generally, the power of a car's air conditioning compressor is not adjustable; it only has two states: on or off. Setting the air conditioning to level 4 will feel cooler than level 1, but this is only due to the difference in heat exchange efficiency, not because the compressor works at a higher power at level 4 compared to level 1.

[McBrooklyn]

There's quite a difference between using gear 1 and gear 4. In gear 1, the fan runs at a low speed with minimal airflow, producing a gentle breeze similar to natural wind, and it's very quiet, making it ideal for sleeping without disturbance. However, it's slower at defogging and removing odors. Gear 4 feels like racing mode, with the fan blowing hard—it can clear windshield fog in just half a minute. But the noise is so loud that it drowns out navigation instructions, and prolonged use in summer can even make you sneeze from the cold. Additionally, gear 1 is more fuel and energy-efficient, while gear 4 forces the compressor to work intensely, especially guzzling gas in older cars. My fuel car burns nearly 1 liter more per 100 kilometers in summer when using gear 4.

[MilesLee]

Using air conditioning at level 1 and level 4 not only differs in wind speed but also operates on completely different principles. At level 1, the compressor works at a low frequency, slowly adjusting the temperature with minimal airflow, keeping the cabin humidity relatively stable and more comfortable. Level 4 is an emergency cooling mode where the compressor runs at full capacity to cool, and the fan operates at maximum load. However, the cold air directly removes moisture from the cabin, which can cause some people's skin to become dry and itchy. Another key difference is the pipeline pressure; at level 4, the high-pressure pipe temperature can rise above 60°C. Prolonged high-speed operation accelerates the aging of the air conditioning pipelines, which is why many cars start leaking refrigerant after seven or eight years.

[JuliaDella]

The difference in AC settings mainly lies in the degree of air vent opening. At level 1, the vent only opens 30%, allowing air to slowly seep through the filter. At level 4, the vent is fully open, even drawing air from the gaps around the filter. However, higher airflow can also blow dust from the filter gaps into the cabin. A practical tip: when sleeping with AC at level 1, adjust the headrest higher so cold air naturally sinks, reducing the chance of catching a cold. At level 4, it's best to direct the vents towards the roof; the cold air bounces down, providing even and comfortable cooling. Another handy trick: use level 4 for defogging the front windshield on rainy days, and the rear defogger button for heating the rear window more effectively.