cd figures (where to find?) - Fuel Economy, Hypermiling, EcoModding News and Forum

watson · 03-17-2008, 10:22 PM

Does anyone know where one can get the cd for existing cars? For example, what is the drag for the opel gt, or the crx. Both seem rather streamlined, and both are available for a reasonable sum. They certainly would seem to be a better start than many others.

Thanks,

Watson

donee · 03-17-2008, 10:56 PM

Hi All,

Here is a start: http://en.wikipedia.org/wiki/Automob...g_coefficients

brucepick · 03-17-2008, 10:57 PM

http://www.mayfco.com/tbls.htm

'Index to Coefficient of Drag for Many Vehicles
Plus Index to Horsepower vs Speed Curves'

Enjoy.
Not every car is in there but there's a lot.

Also you can find c/d for SOME cars at cars.com and autos.com under "research cars", under specifications.

donee · 03-17-2008, 11:02 PM

And This: http://www.mayfco.com/tbls.htm

DifferentPointofView · 03-17-2008, 11:38 PM

The Caliber has the CdA in the owners manual.

I found out the other day that, my Jeep is over 5000lbs!!!.

LostCause · 03-18-2008, 02:13 AM

Quote:

Originally Posted by DifferentPointofView

I found out the other day that, my Jeep is over 5000lbs!!!.

I doubt that. Your GVWR is probably 5000lbs (i.e. the max weight you car is certified to operate at).

Your empty weight is probably 1000-1500lbs less then that figure. I freaked out a bit when I saw my car weighed 4500lb+, until I realized that was GVWR. I didn't feel much better when I learned it was really ~3500lbs...

- LostCause

aerohead · 03-22-2008, 05:51 PM

The 1st generation CRX was given a Cd of 0.32 by HONDA.Later,VW found it to have a CD 0.35.The MITI tunnel had a buoyancy issue that has subsequently been addressed.The 2nd generation CRX HF model is given by HONDA as Cd 0.29.I don't have any data that disputes HONDA's number.As for the GM,Opel,GT ,it's listed in Hucho's book.I don't have that with me.If I could trust my memory,I'd say the GT had Cd 0.45.Perhaps another member is at the computer with the book handy.I'll look when I get home.A friend in college had an Opel,and I remember how I thought the sides and underside were quite" dirty",aerodynamically.Pretty good for late 1960s cars mind you,but bested today by any modern econobox.

aerohead · 03-28-2008, 04:20 PM

Whoops! I went home and grabbed Hucho's book.No mention of little Opel,sorry! Cd 0.45 may not be far off though,as 1968 Corvette Stingray is given Cd0.45,and Opel shares similar architecture,only smaller frontal area.

Cd · 03-29-2008, 01:10 AM

Does anyone here know for certain ( no guesses ) the .Cd of a 1954 Studebaker ( The ones that have been used at Bonneville forever )

I''ve been trying to find that info. for a while now.

Cd · 03-29-2008, 01:23 AM

So what is the .Cd on a 5th generation Civic hatchback ?
Road and Track says in their review of the then new car that the sedan posted a .32 while the hatchback posted a .31 " with the VX model posting a slightly smaller figure due to a small underbody fairing "

I have to question the data because a very similar shaped Ford Focus hatchback has a very large .36.

We have all seen the quote on the Insight write up about the Insight having a .Cd so much better that a Civic hatch at .36 ( which matches the Focus, so is more believable than .31 )
But I wonder if that .36 figure was for the Civic hatch that was out at the time - the sixth generation hatch.

How could the figure fluctuate that much ( And which information can be trusted ? )