What Are the Effects of Opening Windows on the Highway?
3 Answers
Opening windows on the highway can have the following effects: Increased air resistance during driving, leading to higher fuel consumption. When driving on the highway at speeds above 80 km/h, opening the windows creates a wind speed of 40 meters per second. Additionally, oncoming vehicles generate wind speed as well, creating strong convective air currents that hinder the car's movement, resulting in relatively higher fuel consumption. Noise can irritate the eardrums, affecting driving safety. When crossing bridges, tunnels, or open road sections, crosswinds may blow from the bridge surface or tunnel exit. If the vehicle speed is too high and the crosswind reaches a certain level, it can cause a rollover accident. On the highway, opening windows is important. If done properly, it can freshen the air inside the car, providing a good driving environment. If done improperly, it can not only increase fuel consumption but, in the worst case, lead to a rollover accident. Opening windows on the same side is very dangerous. When driving on the highway, it's best to either not open any windows or open only one. Never open two windows on the same side simultaneously, as this causes airflow to rush directly into the car from one side. Passengers on the other side will feel a particularly strong headwind. Even a leaf flying in can have a significant impact and pose an injury risk. If the speed is too high, the vehicle might even be flipped by the airflow like a kite. This behavior is extremely hazardous. It's advisable not to fully open one side's window while completely closing the other side. Not fully opening windows. Some car owners believe opening all four windows is the best way to ventilate the car. However, this method can create chaotic airflow inside the car, causing small items to tilt or even be damaged. If not securely fastened, some fixed keys inside the car might be blown away. Therefore, it's not recommended to open all four windows at the same time. How to open windows safely on the highway: If you must open windows, it's recommended to reduce the speed and check for vehicles on either side. Lowering the speed reduces the intensity of airflow, minimizing the impact of opening windows. We also know that highways have speed limits, so the speed shouldn't be reduced too much. Ensuring there are no other vehicles nearby enhances safety. In short, when driving on the highway, always prioritize safety when opening windows. When driving on the highway and needing to open windows, it's advisable to control the speed and check for vehicles on either side. Lowering the speed reduces the intensity of airflow, lessening the impact of opening windows. Additionally, to expel smoke from the car, the best method is to slightly open the rear left and right windows, just a crack, which can quickly remove smoke from the car.
Driving with windows open on highways actually poses many hidden dangers, which I’ve deeply experienced during long-distance drives. The excessive wind noise interferes with hearing navigation prompts, and missing an exit at a critical moment can be troublesome. Moreover, at high speeds, sand, gravel, and small insects from outside can fly directly into the car, hitting your face and causing significant pain. What worries me the most is the stability issue—opening the windows disrupts the car’s aerodynamics, making the steering wheel feel noticeably floaty during overtaking, especially when encountering large trucks, as crosswinds can easily cause the car to veer off course. Last time, the strong wind blew a plastic bag from the backseat onto the windshield, nearly causing an accident. So now, whenever I’m on the highway, I keep the windows closed and turn on the AC—it’s much safer and more worry-free.
I care most about fuel consumption when driving. Opening windows on the highway is absolutely a fuel-wasting trap. When the speed exceeds 80 km/h, the increased wind resistance from open windows consumes more energy than using air conditioning. I've kept records - for the same 200 km journey, using AC consumes about 0.8 liters more fuel, but opening all four windows can burn an extra 1.5 liters. This is mainly because open windows disrupt the car's aerodynamic profile, like running with a parachute. With current high fuel prices, calculations show open-window highway driving actually costs more, plus the roaring wind noise easily causes driver fatigue. My suggestion is to close windows above 80 km/h - don't sacrifice fuel efficiency for temporary coolness.
