Video: discussion of several GM Volt aero features

[MetroMPG]

Originally Posted by aerohead

Tarzan say turbulence"Good!",Frankenstein say vorticity"Bad!".

Now that's my level of communication! Thanks again, Phil!

[Tango Charlie]

What are 'counts of aero' ? Is this a GM buzz word, or is it an aerodynamics's term?

[Daox]

I believe one count of aero is .001 Cd.

[lunarhighway]

maybe they mean Cd?

i can't watch the vid with audio for the moment (no sound @ work and no internet at my appartment yet) so i'm just looking at the images.

there's an interesting bit about the rear spoiler, where the first version is straight and the second seems to have something which reminds me of a gurney flap.

i've seen certain BMW's wich also have a small gurney flap like spoiler added. and quite a number of cars with a slight upward sweep to the rear spoiler lip.

given it's shown in this video i wonder what it's use is and how it works to aid FE. it would be a relative simple and good looking addition to my car, but i'd like to understand better what it's supposed to do.

[MetroMPG]

Yes, GM used the term "counts of drag" in a quote about side mirrors on the Precept PNGV concept as well. 1 count = Cd .001

Side mirror drag & effect on fuel economy - quantified

[Tango Charlie]

Originally Posted by Daox

I believe one count of aero is .001 Cd.

So 10 counts would be 0.01 Cd. And they got a half mile range extension from that? Wow. Pretty good. I think I'll go ahead and remove the roof rack from my Vibe, even though I wanted to get my SG calibrated first. Too impatient.

[Markmysite]

Originally Posted by Tango Charlie

So 10 counts would be 0.01 Cd. And they got a half mile range extension from that? Wow. Pretty good. I think I'll go ahead and remove the roof rack from my Vibe, even though I wanted to get my SG calibrated first. Too impatient.

That's my biggest issue right now. I didn't start a fuel log until I started modding, and now I want to do everything all at once. I have no clue how much each mod or driving change is actually affecting my MPG. I guess cumulative is good enough to know though.

[SuperTrooper]

I recently became friendly with an owner of multiple dealerships in MA, one of which is a Chevy dealership. We talked this week and I asked him if had heard anything new on the Volt. He'd seen this video and told me that an e-mail had gone around to sales departments weeks ago talking about "substantial" changes in the final design. He was worried it was going to look more like a Malibu since all the engine/drivetrain mules so far are Malibus. That would be a huge mistake. People want the cutting edge styling to match the cutting edge powerplant.

[trikkonceptz]

Originally Posted by Tango Charlie

So 10 counts would be 0.01 Cd. And they got a half mile range extension from that? Wow. Pretty good. I think I'll go ahead and remove the roof rack from my Vibe, even though I wanted to get my SG calibrated first. Too impatient.

Be warned that you will have some nasty holes in the back of the Vibe that you cannot cover. I saw more benefit than problem by removing it, so have at it.

[MetroMPG]

Trikkonceptz: I thought you were going to fabricate something to smooth over those gaps?

SuperTrooper: I think the substantial changes they're talking about are addressed in the video. The car is only going to have some of the features and "design language" of the concept car which was a disaster, aerodynamically.