Archive for the ‘Internal Combustion’ Category


Range extender efficiency – a study of a study

January 3, 2008

With the concept of series hybrids/range-extended EVs growing in popularity, I thought it might be interesting to take a look at a study that was put out a few years ago by San Dimas, CA-based AC Propulsion. AC Propulsion constructed a towable trailer with a range-extender for their tZero prototype car. This genset was based off of a small motorcycle engine – something GM has suggested they might use for some eFlex vehicles.

AC propulsion’s used a 500cc Kawasaki engine rated at 20kW output to maintain their tZero’s battery at around 80% SOC. Without any battery supplementation, the device could achieve between 32-38 mpg. Though an interesting experiment, I think that this study was flawed in a few ways – or at least not completely applicable to future efforts.

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The future of combustion

September 24, 2007

Despite the optimism over the electrification of the automobile, I predict that we will be using the internal combustion engine (ICE) in some form or another for many more years. For one, not everyone will be able to afford a pure EV or even a PHEV, and others may find that their needs simply do not match what the EV/PHEV market has to offer. However, for those who equally accept the ICE and the PHEV, this is actually a rather exciting time because the unique environment of the PHEV gives the ICE a chance to shine like it has never before.

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Taking the Toys to Task

September 13, 2007

Toyota has been on a bit of a PR binge lately, in which they have been taking some shots at GM and the hype surrounding the E-Flex/Volt development. Specifically, one of their hacks in Japan put together an internal presentation where it was claimed that the parallel plug-in hybrid approach was inherently superior to the series configuration. After that presentation was leaked, it caused a bit of a stir in the blogosphere, causing one of Toy’s North American execs the pen the following article as a clarification.

Irv reiterates the Toyota standpoint with the following assertions:

-Lithium ion technology is nowhere near ready for automotive use yet
-GM’s claims of 40 miles on one charge are totally unrealistic
-The series hybrid wastes energy by hauling around a heavy engine that doesn’t directly power the car.
-The parallel plug-in Prius is a super design because it uses a much lighter battery pack and can use the ICE for propulsion, not just electricity.

Now, I work in the sciences, so I always appreciate intelligent skepticism. But Mr.Miller made some sweeping and rather uneducated comments.
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Automotive X Prize entrants announced

August 2, 2007

After almost 2 years of speculation and deliberation, the Automotive X-Prize (AXP) announced its list of registered teams, which ranges from upstart unknowns based out of garages, all the way up to established companies.

I was a big fan of the original X-Prize, but this new incarnation has some conceptual flaws.

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