Sebastian is joined by Jeremy for AutoblogGreen Podcast #23, since Sam was hanging out with Bob Lutz and his Vectrix scooter when we recorded. Jeremy recounts his experience with Piaggio MP3 scooters on a ride from New York to Connecticut, and we move on to talk about the limited Prius supply as of late. We also touch on some developments at GM: the impending doom that may befall Hummer, and the coming of the Volt, which GM wants to build in Detroit. We go on for a while about hybrids and EVs for a while before wrapping up. Thanks for listening, we'll see you soon!

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Scott over at PetroZero had the opportunity to pose some questions to Bob Lutz the other day and, as always, the responses were interesting. First off is the idea of the E-Flex platform operating entirely free of batteries, with the engine/generator simply running continuously and feeding electricity to motor. While this is certainly technically possible, the current E-Flex system is not architected for that possibility. The generator has no direct connection to the motor, rather it feeds the battery. The engine is designed to run at constant speed and wouldn't achieve anywhere near the efficiency if it had to provide transient operation. Because the motor requires more power on demand for acceleration, the engine would have to speed up. In this usage scenario, the efficiency losses of converting mechanical to electrical and back to mechanical power would come in to play as described by Toyota and others when they criticize the whole concept. A conventional parallel hybrid would actually be preferable in this case. The whole premise of improved efficiency from E-Flex is built on the idea that the vehicle will run off grid energy the majority of the time.

The other possibility that Lutz mentions is eliminating the engine/generator and going battery only. This is actually not a new idea and was discussed as a long-term possibility back in late 2006 when GM held the first background briefings on the Volt prior to its auto show debut. The idea is that if battery technology progresses to the point that a Volt type vehicle could provide a reasonable electric range without a range extender just by using a bigger battery, it could easily be done. The idea is mentioned in the first E-Flex technical description I wrote here. Finally, Lutz indicated that within the next two weeks he will be taking an initial test drive in a real Volt prototype. According to Scott this is an actual Volt prototype not a Malibu-based mule. I find that unlikely at this stage. A mule drive is almost a certainty though.

Update: Rob Peterson at GM confirmed that it is only a mule that Lutz will be driving. Actual Volt prototypes are still many months away.

[Source: PetroZero]

Apparently the the spy-shots of a Chevy Volt mule that turned up on-line late last night were not necessarily what they appeared to be. According to GM the photo's in question actually showed a ride and drive mule that is just testing suspension hardware. The gray car we saw earlier doesn't have any of the E-flex powertrain hardware installed. The giveaway would be the absence of a mis-shapen hood on that particular car. The red Malibu you see pictured here is actually one of the powertrain mules that has been circulating the roadways of the Milford proving ground for the last five months. Under that big lump on the drivers side of the hood lies the power electronics module. This vehicle actually has the electric drive motor, the engine/generator combination, power electronic module and a small nickel metal hydride battery pack. The pack is basically being used as a buffer between the engine/generator and motor so that those components can be tested. Powertrain and software engineers are using this car and other to test hardware components and start developing the control software that will make all of this work. Because the battery pack is so small, the engine/generator pretty much runs all the time in the charge sustaining mode that will happen when the lithium ion pack is depleted. The plan is still to start installing the lithium ion packs into mules like this one within the next few weeks.

[Source: General Motors]

Click above for high-res gallery of Chevy Volt mule spy shots

GM has been rather open when it comes to discussing the ongoing development of the Chevy Volt. Check here for our latest round of updates and you'll see that the Volt is moving along quite nicely. Still, there's a long way to go before the vehicle is ready for the road. The test track though, as you can see in the photo above, is another story entirely. According to Brenda Priddy's spy photographers, the Volt's E-Flex underpinnings are currently being tested cloaked under last-generation Malibu bodywork. We knew they'd be coming and are glad to see some visual proof. The production Volt will be based on GM's Delta platform, not the Malibu's architecture. The mules you see in these shots should contain an electric motor, an engine/generator set and some of the first battery packs from CPI and Continental. We're anxiously awaiting our chance to get a ride in one of these Malibu-bodied E-Flex mules.


[Source: Chris Doane for Brenda Priddy and Co.]