Dirty rear end

[Paynewright]

Driving around this (so called) winter I’ve noticed the barn door windows get dirty very quickly with traffic film. Glad I have the wipers! I assume its the same for the tailgate?

Just wondered if door spoilers change the aerodynamics and stop this? Or would something like rainex help?

Regards
Ian

 

[dubber36]

The purpose of a rear spoiler (although not necessarily for a brick shaped van) is to produce aerodynamic downforce. The byproduct of this is additional turbulence where the air passing over the vehicle is mixed with the air passing under it. This swirl of air picks up the dirt from the road and deposits it on the vertical surface on the rear of the vehicle. So adding a spoiler will make the situation worse as it creates more turbulence.

When the van gets properly dirty, you'll see that VW have done what they can in managing the turbulent airflow, as the dirt is predominantly stuck to the center of the rear doors or tailgate, leaving the lights relatively clean. It's therefore a case of your rear windows getting dirty being the lesser of two evils. Having a dirty rear window is no different to having a solid rear door, so not considered a safety concern.

 

[drays]

The air is certainly very turbulent at the rear, so the rear window does get dirty very quickly. Also, if your rear screenwash nozzle is as pathetic as mine it doesn't have enough pressure to reach beyond half way up the rear window, so it doesn't clean properly!

 

[Paynewright]

I’ve adjusted my nozzle!

 

[drays]

How far up the window can yours reach???

 

[The Van Cave]

I’ve adjusted my nozzle!

I had to adjust mine too. When I bought the van it did a great job of soaking any vehicles heading in the opposite direction to me! It was pointing slightly backwards and straight across the road.

 

[dubber36]

I like the dirty rear look when the van is especially filthy.

I cursed my wife the other day when she'd driven it and washed the rear window. I had to wash the van and start the dirtying process all over again.

 

[Paynewright]

How far up the window can yours reach???

well over half way! It does take a while to build up a bit of pressure!

 

[drays]

well over half way! It does take a while to build up a bit of pressure!

I'll have to get adjusting in that case. I assumed it was just a bit shit!

 

[Paynewright]

Just needed to adjust it - old style ball / socket type.

 

[Trouts]

How far up the window can yours reach???

this is the VW T6 geeks* version of a pissing up the wall contest right?!




* term used with utmost affection!

 

[drays]

this is the VW T6 geeks* version of a pissing up the wall contest right?!




* term used with utmost affection!

 

[Merv555]

Hi,
I seem to get my tailgate very dirty, I have mud flaps all round.
Is this common or is it to do with being four wheel drive?

 

[kurienp]

... to do with the brick shape. A rear spoiler does help reduce.

 

[Dellmassive]

non of the above.

its to do with aerodynamics unfortunately.

the van back causes a low pressure area of circulating air that causes all the road grim to get stuck to the rear doors/tailgate.

,,
#
i believe the technical term for it is called wake vortex and drag coefficients

...

mudflaps wont help out with this one - just regular jet washing to keep it clean.



(This is also why most estate cars have rear wipers, yet the normal saloon version dont, its to do with the flatter angle of the rear window with regards to the floor and direction of travel. --- The saloon has better aerodynamics which keeps the air flowing faster so the dirt doesnt get stuck to the glass. )

 

[MrSkip]

non of the above.

its to do with aerodynamics unfortunately.

the van back causes a low pressure area of circulating air that causes all the road grim to get stuck to the rear doors/tailgate.

,,
#
i believe the technical term for it is called wake vortex and drag coefficients

...

mudflaps wont help out with this one - just regular jet washing to keep it clean.



(This is also why most estate cars have rear wipers, yet the normal saloon version dont, its to do with the flatter angle of the rear window with regards to the floor and direction of travel. --- The saloon has better aerodynamics which keeps the air flowing faster so the dirt doesnt get stuck to the glass. )





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Perfect explanation

 

[Merv555]

That explains that thanks.
Weekly wash it is then.

 

[Jezma]

I've enjoyed the innuendos an this thread has plenty

 

[JOG]

I've enjoyed the innuendos an this thread has plenty

I'm horrified..............sitting here chewing my tongue in case my feeble little brain explodes!!!

 

[VanDamMan]

Even with its new rear end…The Sportline will still get a dirty rear….on mine it’s always the Bottom that gets the dirtiest…..but I always jet wash first as you don’t want grit on my paint work…and it’s given a good wipe after