Not to dig up an old thread, but I've been looking in to "upgrading" my civic body style and buying a HB. I found the data on the cd of a 6th gen civic HB, but the coupe (what I have now) is missing. I found data on it to add, and this seems like a good thread to do it.
1996 Honda Civic EX Coupe
Wheelbase 2621 mm 103.2 in
Track front 1476 mm 58.1 in
Rear 1476 mm 58.1 in
Length 4448 mm 175.1 in
Width 1704 mm 67.1 in
Height 1374 mm 54.1 in
Length: wheelbase ratio 1.7
Ground clearance 165 mm 6.5 in
Kerb weight 1127 kg 2485 lb
Weight distribution
(Front) 62.00 %
Fuel capacity 45.1 litres 9.9 UK Gal 11.9 US Gal
Drag coefficient 0.340
Bore × stroke 75.00 mm × 90.00 mm
2.95 in × 3.54 in
Displacement 1.6 litre
1590 cc
(97.028 cu in)
Transmission 5M
Top gear ratio 0.70
Final drive ratio 4.25
Snipped from
here
So it looks like at least in the 6th gen (96-00), the coupe has the best Cd in the generation. I think if a kammback or boat tail were added to the HB, the Cd of a coupe. Any data on how many hundredths of the coefficient a kamm has successfully decreased?