[aerohead]

Originally Posted by RobertSmalls

Two other independent lists:
Automobile drag coefficient - Wikipedia, the free encyclopedia
Automotive aerodynamics - Wikipedia, the free encyclopedia

What I really want to see is CdA data on modified cars. So, in .csv format:

Make,Model,Year,Cd,Height (In),Width (In),Frontal Area (ft^2),CdA
Aptera,2e,prototype,0.15,,,19.9,2.98
Volkswagen,1L Concept,,0.15,39.6,49.2,11.0,1.63
Aerocivic,Civic Hatch,1992,0.17,50.9,66.9,19.9,3.38
GM,EV1,1996,,,,,3.95
Subaru,Legacy Wagon,1995 - 1998,0.32,57.1,67.5,22.5,7.19

Aerocivic data from aerocivic.com. I'm sure the coastdown testing generated CdA data, which was then divided by a guesstimated value of A. I then multiplied the reported Cd by my own guess of A. I would love to know if this matches the CdA from the coastdown testing.

If so, then the conclusion is powerful: Most compact cars have very similar CdA, and I would only gain a 14% improvement in aerodynamics by trading my Subaru wagon in for a Civic hatch. Even the Insight is only 30% better than my car, but the Aerocivic moves through the air with 49% the effort of the Subaru.

If you want a slick car, you have to build it yourself?

If anyone has measured the CdA of their cars before and after aeromods, I'd love to see your results.

The '70 VW bus was estimated at Cd 0.285 vs 0.43 based upon 55-mph mpg.
The '84 CRX was estimated at Cd 0.235 vs 0.32,based upon top speed and 55-mph mpg.
The T-100 was measured at :
*Cd 0.268-0.267 vs 0.44 as driven
*Cd 0.251 with mirrors folded
*0.24 with mirrors deleted
The DARKO tunnel's numbers are 8.77% higher than the A-2 tunnel.
If the T-100 had been measured at A-2,the Cds might have been:
*0.244 as driven
*0.229 with mirrors folded
*0.219 with mirrors deleted
*At Cd 0.268,the top speed would be 123-mph vs 109 mph for a re-geared T-100.
*mpg at 65-mph was 34 vs 25.