cheap areo fix! (wash & wax your car)

[alcivic]

one way to increase mpg is to wash your car and wax it. this will reduce air resistance thus increase mpgs!!!

[SVOboy]

Got any data to back that up?

[Cd]

Actually, I have read that several times before too.

BUT ...this comes from sources that apparently do not research the concept.

Sorry to tell you ... but it's myth.

I haven't seen you post before. Welcome to the forums !

[malibuguy]

HotRod magazine did a thing on aerodynamics at a windtunnel location, & the 'expert' that runs the windtunnel says a dirty car has the same drag as a clean car, it makes no difference

it doesn't say it here, this is the article, but the online articles tend to leave out stuff thats in the magazine

http://www.hotrod.com/techarticles/b...ips/index.html

[ttoyoda]

one way to increase mpg is to wash your car and wax it. this will reduce air resistance thus increase mpgs!!!

It is true for a lear jet. A car does not go fast enough to make a difference.
The boundary layer on a car is thicker than the roughness of the dirt film.

[cfg83]

alcivic -

I have head that this is true for airlines because they are able to save fuel doing this. I don't think it translates to cars because they don't travel fast enough. Didn't UPS have an ad where they were washing their big brown jets a long time ago?

Here is the only tangential example I could find :

Clean Drives Airline Fuel Efficiency - June 10, 2008
http://greentechnolog.com/2008/06/cl...fficiency.html

... "American and Southwest are washing a handful of jet engines each night, a process that used to happen only during thorough maintenance overhauls. Southwest figures it has already saved $1.6 million in fuel costs since April by reducing the drag caused by dirt and debris. " ...

CarloSW2

[metroschultz]

I always believed the opposite.
A dirty car,(not filthy and covered in droppings) would get slightly better CdA.
Similar to the way dimples on a golf ball work.
Now somebody (not me, too lazy) is gonna hafta research.
Schultz.

[wagonman76]

Originally Posted by metroschultz

I always believed the opposite.
A dirty car,(not filthy and covered in droppings) would get slightly better CdA.
Similar to the way dimples on a golf ball work.
Now somebody (not me, too lazy) is gonna hafta research.
Schultz.

Well I think Im just going just to leave well enough alone with my hood thats been rough and sun faded since I bought the car 5 years ago.

[ttoyoda]

Speed of a golf ball:

Before I began the optimization process, I hit more than 100 balls on the range to get loose. At the launch monitor I started with my 7-degree Ping driver. The computer showed my ball speed was 150 miles per hour, my launch angle 14 degrees and my spin rate 4,400 revolutions per minute.

http://findarticles.com/p/articles/m...4/ai_101967391
Faster than my driving. Tiger Woods gets up to 180 - 200.

[Cd]

Originally Posted by malibuguy

HotRod magazine did a thing on aerodynamics at a windtunnel location, & the 'expert' that runs the windtunnel says a dirty car has the same drag as a clean car, it makes no difference

it doesn't say it here, this is the article, but the online articles tend to leave out stuff thats in the magazine

http://www.hotrod.com/techarticles/b...ips/index.html

That's the source that I was going to use.

Also, windshield angle steeper than 45 degrees is just for 'looks' It does nothing to improve the cars drag - ( that one really took me by surprise! )