Honda Car Forum

People say that "due to physics" dust accumulates in rear of SUV windshield and not on that of sedan, can some one explain in somemore detail why?

i would say because the suv sits higher than the sedan therfore allowing more dust and debris to flow through the undercarrige.

With the squared off back of an SUV, the wind swirls up behind it, carrying road dust and water.I have a spoiler on my Subie to pevent that from happening, and rarely use the rear wiper.

some sudans do, even some sports cars do, c'mon' man, look around town a bit. it's okay though, maybe you can't. sorry about that. but yes, some cars do and some cars don't...

Air flow? The air flow makes it more difficult for material (dust, snow, etc.) to accumulate on the window.

because big SUV,s have the big window,,and the way the vehicle is built,,it catches a lot of dust and dirt,,and needs to be cleaned off,,most cars have a trunk area,,and this helps prevent things from getting slung up on it,,there are some sedans that have them,some Honda cars have them,,but they are needed on a SUV,,other wise you,d be out there cleaning he back glass all the time,,ad this would be no fun in the rain,,i hope help,s,good ,luck.

As a car moves forward, the air that flows over the top has further to travel than the air passing underneath. This causes a reduction in pressure of the air "falling off" the back of the vehicle compared to the air passing underneath. The principle is similar to the lift effect on an aircraft wing.This variation in pressure causes the air exiting from under the car to move upwards into the lower pressure area. It brings with it dirt, moisture and debris from the road surface thrown up by the wheels.The general turbulence of this air causes it to swirl upwards at the rear of the vehicle "Throwing" the dirt onto the rearmost part. In a SUV this includes the rear window, in a sedan this is the end of the boot (Trunk in USA speak).A sedan also has a lower profile against the air and is more streamlined. This has the effect of reducing turbulence and causing fewer air vortices behind it and throwing up less dirt and moisture.This is a simplification of the science of streamlined and turbulent airflows but should give you an idea why the back of the SUV gets dirtier and needs that rear wiper

It is true most SUV while traveling creat a low pressure area behind the vehicle allowing more dust water to gather on back glass plus SUV's do not have a trunk so the back window is the back of the vehicle. Mini vans are the same way.