Quote:
Originally Posted by lunarhighway
i wonder how usefull drag coeficients really are for comparison ....
i assume that with more accurate testing these days...such as spinning wheels, etc, drag coeficient would come out higher, because more detailed testing will reveil more drag.
i've heard they're also dependant on the actual wind tunnel used.
so how comparable are drag coeficients of something that was tested 20 years ago in a different wind tunnel with something tested today. or two current cars tested in different wind tunnels, wich they very likely will be if they're different brands.
that said, the lower is obviously the better, and 0.28 is not something to brag about... the opel insignina/buick regal is build on the same platform ...the the ecoflex has a claimed 0.26Cd!
than again drag coeficient seems very dependent on things like tire width and engine choise, different (bigger)engines needing more cooling = less factory grill blocking
this combined easily changes the Cd by 0.02, without any visible external changes.
the good thing in all this is aerodynamics is back in the marketing talk...
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I'd like to see them listed on the new car window sticker along with the frontal area.
It would be to the consumer,as square footage and thermal insulation ratings would be for a home.
The Cd would be the equivalent of the heat transfer coefficient of the home which is the inverse of its composite R-Factor.
And the frontal area would suggest the CFM/CMM in which your going to push that R-Factor.
Driving speed would be the same as design indoor temp..