Hola
 

Hello Ecomodders.

I've been exploring your site for some time and find it highly interesting. May be I can contribute a bit.
I'm afraid I'm not strictly a partisan of mileage or ecology http://www.foren4all.de/images/smilies/mauer.gif , but of efficiency. The late tends to go hand in hand with the former however :) .

As an example, I own a '91 Opel Calibra whose engine I heavily fiddled from 115 to 142HP; top speed is now 220kmh/148mph. Bad recipe for good mileage you'd think, but the more efficient engine, allied with the superb aerodynamics (Cd 0.26), means this 1200kg/2650lbs car now swallows just 42mpgUS @ 95kmh/60mph and 31mpgUS @ 150kmh/95mph ;) .

See you around.

TELVM -

Welcome to EM! I think lunarhighway once told us that the Opel Calibra was one of his favorite cars because of it's Cd :

Attachment 1750

Beautiful car.

CarloSW2

Welcome! Love the calibra, :)

Thanks for the welcome!

The aerodynamics of the Calibra are state-of-the-art even today, and it was a world record when introduced in 1989.

http://img98.imageshack.us/img98/228...evla018cc3.jpg

This car has Cd 0.26 and frontal area = 1.93 square meters. So its SCd (the real parameter) is 0.5018 in metric. An Audi A2, with 0.25 x 2.18, has worse aerodynamics at SCd = 0.545 ;) .


For those interested in aerodynamics here goes a nice article on the subject, at the end they analyze the aero tricks used on the Calibra:

http://img34.picoodle.com/data/img34...cm_87f06ba.jpg

http://www.freewebs.com/calibra4ever/windtunnel.jpg

http://img169.imageshack.us/img169/5...l3smallai1.jpg

http://img169.imageshack.us/img169/6...l4smallyy4.jpg

TELVM -

I looked at the PDF and found a cool picture of wheel skirt aero analysis :

First Generation Audi A3
Attachment 1751

This is nice because it provides a starting point for others to "guess-timate" what the benefit would be of adding a wheel skirt.

Example: The "normal" mod of adding a rear wheel skirt adds an 0.006 Cd benefit.

CarloSW2

That is a nice car! Welcome to ecomodder

What strikes me in the slide is the 30-35% of total drag attributed to wheels and arches. That's a lot of drag for a small area when you consider the whole body surface. This might deserve more thinking than I originally thought.

Tricks to reduce wheel drag in the Insight (0.25 x 1.9 = SCd 0.475):

http://www.insightcentral.net/_images/enstrakes.jpg

http://www.insightcentral.net/_image...nt-airflow.jpg

http://img37.picoodle.com/data/img37...om_1687a7b.jpg

InsightCentral.net - Encyclopedia - Honda Insight Aerodynamics