As we have just heard, GM's director of E-Flex design, Bob Boniface spoke at the Center for Automotive Research (CAR) meeting and at the same time new detail shots of the production car were released. Soon after that I had the chance to ask Bob some questions about that and other issues.
A key rumor dispelled is that the additional 6 miles of AER achieved by the redesign is NOT added to the 40, it's just that the show car was unable to achieve that goal. Read the whole interview below:
So did you just release images of the front quarter and the rear shot today?
During the presentation I showed some mapping images cropped of the rear of the car. These were not for public consumption.
As part of the aero story I showed chunks of the show car and the same chunks of the production car and I talked about how and why they were different. I showed the rear corner and the front corner.
And I also discussed and showed images of the side view mirror and how we modified it for aerodynamic performance. I showed before and after shots of the rear spoiler and how it was aerodynamically modified.
What's different about the rear spoiler?
It is higher and further rearward in the production car. What I showed is how we applied a higher millimeter tall lip to the end of it and how that resulted in a 5 count reduction in aerodynamic drag. 10 counts of aerodynamic reduction is equivalent to .55 miles extra driving range. The new spoiler and rear view mirror each removes 5 counts of drag resulting in a half mile more range.
In aggregate from the show car to the production model we've taken a total of 120 counts out, which equals 6 miles more range. However that 6 miles is not added to our 40 miles. We're not giving you 46 miles now. It's just that the original show car surface would not have delivered the promised 40 miles of range.
So the production car has a CD .12 lower than the show car?
Yes. The point of the demonstration was why we had to change the show car and how it changed.
So is the design now final or are there any further tweaks?
Aerodynamicallywe have met our target. As far as the styling goes, there will be essentially no changes from where we are today. We do have some more detail changes needed for manufacturing but nothing that anyone would notice if they were to see the car today.
Will the front grill be closed on the production vehicle as it appeared on the recent ABC news video?
It's nearly completely closed. We take in a little bit of air along the side of the lower portion of the grill but its essentially closed. All of the air comes in at the bottom of the fascia, at the bottom of the bumper because the cooling requirements are such that we were able to send the air around the car to the motor compartment for cooling.
Can you say what size wheels will be on the production car?
No. They're big enough.
Are you using tires that will run to flat so you dont have to carry a spare in the car?
We are not currently packing a full-sized spare in the car. We have provisions for getting home in the case of tire failure. We are not carrying a full sized spare because it will add extra mass and weight.
What can you say about the roof, will it be transparent, or have solar panels?
Its still a surprise for you.
Will there be a sunroof option?
We aren't talking about vehicle options at this point.
Did you have to modify the wheels from the showcar so that they would be more aerodynamic?
We tried to stay as close as possible to the concept's wheels. Aerodynamically speaking wheels are a very difficult thing to nail down. They need to be open to allow for brake cooling, but you dont want the surface to stick out into the airstream. Another big thing about the wheels' design is that it would be mass-efficient, so its a pretty lightweight wheel. It may change slightly more as we're still doing wheel testing in the tunnel.
Will the body be made out of steel or will you use special lightweight components?
There are a couple of areas where we have included some lightweight materials but in general we want to stick to conventional manufacturing processes and materials to keep costs down.
How different will the production car look from the showcar?
It is changed a bit from the showcar, the proportions have changed for a variety of reasons. But it is still a very good looking car. It is still very sporty. In a lot of ways it looks better than the showcar. The surfaces are much more sophisticated. I love the car, I think its fantastic. It's not apologetic.
So there's nothing on the road today it looks like, and it won't look like a Prius?
You'll know its a Chevrolet and you'll know its a Volt. But does it look like any of our competitors vehicles? I don't think so.
Were you able to keep the greenhouse height low?
We made the roof go as low as we could without compromising safety or comfort. We kept the roof low for style but also primarily for aerodynamic reasons. There's the coefficient of drag and there's aso the frontal area of the car. By keeping the roof down, we present a smaller frontal area.
Can you say whether there will be one or two charging ports?
The charging port or ports are in fact well-placed.
It was reported that you are revealing the car in Paris in mid-October, is that publicly confirmed?
We have not revealed when we are going to show the car. Any reports to that effect are conjecture.
Are you presently designing other E-Flex vehicles?
Yes, we are working on other vehicles. We are working on more than one other vehicle that uses this architecture and powertrain. I'm certainly not going to tell you what they are at this point. The E-Flex powertrain is going to spread across more vehicles than just the volt.
Are you keeping the theme of how the glass goes down into the body?
Its safe to say we are keeping some of that theme. Not only is it cool to look at but it improves rear visibility.
Is the interior theme components and finishes final?
We are very close to being finished with the interior surfaces. The theme is essentially set. We're playing with grains and gloss levels at this point. We know what the content is going to be. We're down to the last, last little details.
With respect to the ipod-like dash, are there touch screen controls?
It's going to be two dash screens, the center one is touch sensitive.
Is there going to be internet access in the car?
I don't want to talk about that.
Will there be running prototypes that look like the final car by the end of this year, as others have reported?
Representative body will not meet representative powertrain until sometime next year, and that's in a developmental form.
Is the Hammtramck plant undergoing any retooling yet for the Volt?
We don't know about that.
What was the reaction of the consumer focus group who actually got to see the production Chevy Volt?
It was overwhelmingly well-received. You didn't hear any drawing of comparisons to other cars on the market, "it looks like that..etc". I was absolutely blown away by the positive reception to the car. Regardless of the powertrain technology, they loved the car. You cant give a designer a better compliment than that.
[UPDATE: Leaked pic of full production back added, thanks to AndyChuck for the tip and credit to John Voeckler of hybridcars.com ]
Also here's a video of the presentation thanks to Sam Abuelsamid of Green Fuels Forecast :