Should You Use Internal or External Air Circulation When Driving on the Highway in Summer?
3 Answers
When driving on the highway in summer, you should use the external air circulation. Appropriately open the windows or turn on the external air circulation: During long drives on the highway, it's advisable to slightly open the windows or activate the external air circulation to maintain fresh air inside the car and prevent dizziness caused by lack of oxygen. When sleeping in the car, do not close the windows or turn off the external air circulation. Activate the external air circulation: Whether to use internal or external air circulation on the highway depends on the season and weather. When the weather is comfortably cool, you can turn on the external air circulation; when it's hot, avoid using the external air circulation. On rainy days, switch to internal air circulation and also turn on the defogging function to prevent fog from obstructing your vision.
In summer highway driving, I recommend prioritizing recirculation mode. When you first turn on the AC, the car feels like a steamer - recirculation cools it down faster by only circulating the chilled air inside, without struggling to cool down scorching outside air. During long drives if it feels stuffy, switch to fresh air mode for 5-6 minutes every half hour. But remember to switch back to recirculation when stuck in traffic or behind trucks spewing exhaust, to avoid inhaling fumes. This alternating method saves fuel while keeping comfortable, without overworking the noisy AC system.
When driving on the highway in summer, I first use the recirculation mode to quickly cool down the car. Once it's comfortably cool, I switch to the fresh air mode. The fresh air mode allows outside air to come in, preventing drowsiness caused by high carbon dioxide levels, which is crucial for long-distance driving. However, don't forget that the fresh air mode draws in hot air, making the air conditioning work harder to cool, which also increases fuel consumption. So my experience is: after the temperature drops, mainly use short bursts of fresh air mode, and immediately switch back to recirculation when entering tunnels or areas with poor air quality. Additionally, regularly check tire pressure and coolant levels, as vehicle condition is especially critical in hot weather.
