Why don't sedans have rear wipers?

When a car is moving, there are two basic aerodynamic forces that mainly affect the car: lift and drag.

Drag is the force exerted by the air on a car as it moves. The drag is parallel to the moving surface of the car and is proportional to the speed. The faster the car moves, the greater the drag.

According to aerodynamic theory, when a car moves, the air flow above the hood travels a longer distance than the air flow under the car. At that time, the different speeds of the air flows create a pressure difference, thereby creating a lift force perpendicular to the road surface.

This lifting force will reduce the grip of the tires, as well as carry dirt up, stick to the rear of the car and create air turbulence behind the car.

Two main aerodynamic currents influence vehicle performance.

According to research by car manufacturers, during the movement, due to the design characteristics of the vehicle related to the height, body design and rear window size, the air turbulence area behind each car model is also different. This turbulence directly affects the amount of dirt that sticks to the car, especially when the car is operating at high speed.

For sedan models with a long rear end and rear windows tilted at a large angle, less dirt will stick to this part of the glass.

As for SUV, CUV or hatchback models with straight rear design and integrated rear window, they are very easy to get dirty during operation. Therefore, SUV models need wipers to help clean the rear window.

For cars equipped with rear windows that can be opened and closed, drivers need to pay special attention to absolutely close the car doors when moving, because the swirling wind will sweep toxic emissions from the exhaust pipe into the car.

This turbulence directly affects the amount of dirt that sticks to the vehicle.

Along with that, due to the characteristics of the rear window of sedan models being quite large, if the wiper is made for the rear window, this wiper part will be as large as the front windshield wiper, making the rear of the car lose its aesthetic. Not to mention that because the trunk of the car is designed separately, the arrangement of the rear wiper system will be very complicated and expensive.

Meanwhile, for hatchbacks, SUVs, and CUVs, the rear window is often smaller and is attached to the trunk door, so it is quite easy to install a rear wiper. For these reasons, today's sedans often remove the rear wiper system.

Source: https://xe.baogiaothong.vn/vi-sao-xe-sedan-khong-co-can-gat-mua-phia-sau-192240115110335387.htm