I sat down for a brief Q and A with Frank Weber. He is the vehicle line executive for the Chevy Volt and all of E-Flex systems for GM. He knows a lot about what’s going on and is very forthright and forthcoming.
What was GMs motivation to build the Volt?
Societal challenge. Look at the future what you see is that not the industry nor any individual OEM can afford not to believe that this is next big step. Because it is the only technology currently available that can make a fundamental difference. People say “yes but you do hybrids”, but this is there to improve fuel economy above regular fuel-consuming vehicles. Then you look at the data that we currently have on the Volt, and we did intensive work. What we did was in Southern California there are data released from the regional traffic survey, over 600 people had data recorders in their vehicles to see “how long did they drive”, “how demanding was their driving”, lots of data, and we looked at it and we said “What difference would the Volt make in that context relative to hybrids, plug-in hybrids, and conventional vehicles?” The data is just amazing. They had engines starting ten times, we’d have it starting one time, reducing emissions by 70%. When you look at the fuel economy in the end and you saw how many percent versus conventional, you would be at twenty percent of fuel consumed for those drivers, and by the way, those were regular drivers, and SUVs and everything, so this was not a special group.
With the Volt what you see is this is the only way to produce (the energy) independence that we were looking for, and the 40 miles, and this is what made us so comfortable that the concept was right, will really be for a majority of drivers, because the only thing that counts is what will be the reality when you drive this vehicle, is the guy able to say the week has seven days and I will be able to drive six of those without burning any fuel. This is whats going to happen.
If you think this concept through its not about whether you have then once a week the engine will start and burn fuel, this is fine and give people the security that they can do everything with this vehicle that they are used to, but what really counts is what will happen with daily driving in a real world environment. There many people have not even understood how significant the changes are that that this concept will introduce.
The Volt development program is unique because it is parallel in that you are developing the pack at the same time as the rest of the car instead of in serial order?
(Normally) What you would do with the propulsion train and the battery side is you would have a what we call a decoupled or pre-development of that activity, only the moment you know that this is all working and you have tested it then you would start the actual vehicle program.
What we have done is we said to save time, (considering) our confidence with the battery technology and the propulsion technology is so high that we will start the vehicle and the propulsion/battery at the same time, except that this is introducing a higher risk to the development process. What we are doing with this is that we will have the tests of batteries in cars available in early 2008. I’d be surprised if things occur that were not foreseen, although this might happen. We still think it is still the better way to accept risk and build up hardware for the real production vehicle. It speeds up things dramatically.
Beside the battery packs, do you already have all the rest of the hardware for the vehicle functional, for these development mules, i.e the motor control systems, and generator, etc?
What we are doing is we are leveraging, we have a powertrain portfolio because of the strong hybrid and 2-mode hybrid, there is a lot of electric drive experience, and we have the Equinox fuel cell vehicle which is electric, and what we are now doing for the Volt is we are combining those efforts and are not developing everywhere, especially in places where it is not necessarily unique, developing everywhere new components, so the regenerative brakes are just another generation of what we are doing on the two-modes, so we are combining everywhere now pulling together this portfolio of fairly reliable components where we have some background.
Is the electric motor for the Volt the same as what you already have in the 2-modes or fuel cell Equinox or new and different?
It is a different motor specifically designed for the performance needs of the Volt. We will have the first prototypes soon, but as a physical part it is currently not available. We are talking about 115 kW of peak power and this is not something we have around. The hybrid motors don’t need this power. It is a different configuration.
Are you considering different options for generator configuration, for example a parallel design when in charge-sustaining mode?
What we always said is clearly, we have a simplified gasoline or biofuel engine on-board that is only there to generate electricity, and we don’t want to introduce more complexity to the design. Many discussions around the engines itself have been had whether it is diesel or not, but in the end I said I really don’t care because it is an engine that is only there to generate electricity and we will do everything to simplify wherever we can.
If the engine is only there to generate electricity why don’t you use a turbine or a Stirling engine?
What you will see is midterm and longterm there might be other solutions for how you generate electricity but since we said time is important and being fast is important, and also commercial viability is important you will leverage what you currently have in your portfolio, picking up “family zero” small displacement gasoline engines. By leveraging existing powertrain components means for us limiting engineering risk, being fast in execution, and being at a cost point where all those, what you’ve described, advanced solutions that are currently not available, would not be affordable. In the end, these don’t make much of a difference, because we dont want to burn gasoline to generate electricity, this is not the idea of the vehicle. So there will be alternative solutions in the future but for the time being I think we are more comfortable in taking something that we have.
Have you chosen the exact engine that you want to use?
The one that you saw in the show car last year is a “family zero” engine. We are currently working to optimize the specific setup for it, but we will be working off that specific engine.
This entry was posted on Monday, February 18th, 2008 at 6:00 am and is filed under Engineering, GM Q and A, Original GM-Volt Interviews, Production. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.