We’d like to remind Forumites to please avoid political debate on the Forum.
This is to keep it a safe and useful space for MoneySaving discussions. Threads that are – or become – political in nature may be removed in line with the Forum’s rules. Thank you for your understanding.
📨 Have you signed up to the Forum's new Email Digest yet? Get a selection of trending threads sent straight to your inbox daily, weekly or monthly!
The Forum now has a brand new text editor, adding a bunch of handy features to use when creating posts. Read more in our how-to guide
Why are the rear ends of cars always the dirtiest part?
![[Deleted User]](https://us-noi.v-cdn.net/6031891/uploads/defaultavatar/nFA7H6UNOO0N5.jpg)
[Deleted User]
Posts: 0 Newbie
in Motoring
The back of my car is always filthy yet the front is relatively clean. Why is this?
0
Comments
-
Because the movement of the car through the air lowers the air pressure at the rear end. Effectively the car sucks the dirt onto the rear.I'd rather be an Optimist and be proved wrong than a Pessimist and be proved right.0
-
Basic aerodynamics.
Some manufacturers pay more attention to the airflow around the rear than others, and so some cars keep the rear cleaner than others.0 -
Hatchbacks, people carriers, vans etc. will tend to create lower pressure at the rear due to their shapes (less streamlined), and so "suck" dirty air onto the rear of the vehicle. The faster you go, the lower the effective pressure so the greater the issue.
I notice this in my Golf when it's wet and I'm on the motorway - the rear wiper has to be used a lot to keep the rear screen clear.
Obviously the dirt is coming from wet, grimy road surfaces.0 -
Mostly as above, but exhaust plays a part too, diesels get dirtier faster. The above effect traps exhaust gases in that vacuum behind the vehicle.
This is why on 4x4 with opening rear windows (Vitara and Freelander spring to mind), the manufacturer will normally state not to drive with only that rear window open, as exhaust gases could be pulled into the car. Opening a side window + the rear has the effect of changing the aerodynamics, removing the vacuum effect by pulling air through the car.“I may not agree with you, but I will defend to the death your right to make an a** of yourself.”
<><><><><><><><><<><><><><><><><><><><><><> Don't forget to like and subscribe \/ \/ \/0 -
Thanks everyone0
-
My rear end is also my dirtiest part0
-
My Sierra hatch doesn't get anything on the rear window if you keep it moving, the subtleties of vehicle aerodynamics.0
-
My Sierra hatch doesn't get anything on the rear window if you keep it moving, the subtleties of vehicle aerodynamics.
That's because it's a bloody jelly mould, nothing, not even dust would be seen dead on it
“I may not agree with you, but I will defend to the death your right to make an a** of yourself.”
<><><><><><><><><<><><><><><><><><><><><><> Don't forget to like and subscribe \/ \/ \/0 -
Strider590 wrote: »Mostly as above, but exhaust plays a part too, diesels get dirtier faster. The above effect traps exhaust gases in that vacuum behind the vehicle.
This is why on 4x4 with opening rear windows (Vitara and Freelander spring to mind), the manufacturer will normally state not to drive with only that rear window open, as exhaust gases could be pulled into the car. Opening a side window + the rear has the effect of changing the aerodynamics, removing the vacuum effect by pulling air through the car.
And you shouldn't drive with the rear boot or hatch open to carry long stuff for the same reason and it usually says so in the car handbook0 -
Is it a soot chucker?0
This discussion has been closed.
Confirm your email address to Create Threads and Reply
Categories
- All Categories
- 354.6K Banking & Borrowing
- 254.5K Reduce Debt & Boost Income
- 455.5K Spending & Discounts
- 247.5K Work, Benefits & Business
- 604.4K Mortgages, Homes & Bills
- 178.6K Life & Family
- 262K Travel & Transport
- 1.5M Hobbies & Leisure
- 16.1K Discuss & Feedback
- 37.7K Read-Only Boards