Quote:
Originally Posted by Bror Jace
Guys, there was a thread here not long ago where an aeronautical engineer weighed in. Basically, there are two forms of drag (I forget the terminology) and the drag associated with smooth, slippery surfaces doesn't come into play until you are travelling hundreds of miles per hour (aircraft speeds).
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Quote:
Originally Posted by Bror Jace
Here is one thread that talks about drag caused by the condition of the surface ... but it's not the one I was thinking of.  |
Good point!
If a shiny, clean car DOES get better FE, it would only be the case at highway speeds!
A little dust on the surface would not have any measurable effect on the MPG, but if there are sizable clumps of dirt on your car that significantly alters the air flow along its surface, then it WOULD reduce your gas mileage.
Wax, et al, and Rain-X can only improve matters...
