On 30 Mar 2013 at 6:27, tomw wrote: > If the Volt is a "hybrid" what is the (non-plugin) Prius?
Until the automakers (notably Toyota and Honda) claimed it, the term hybrid had a widely accepted meaning: a vehicle which used both a fueled drive source and an electrically-powered drive source, normally an ICE and a motor. Each of them operated on a different energy source. The vehicle could move under the power of either, and sometimes both. It was understood that a hybrid vehicle could be driven for a usable distance in full electric mode. True hybrids come in two basic "flavors," series and parallel. The series hybrid has no mechanical connection between the ICE and the wheels; the ICE drives a generator which charges the battery and/or supplies electricity to the drive motor. The parallel hybrid has the ICE mechanically coupled to the drivetrain. In the past, series hybrid proponents argued that by operating the ICE at a steady speed (always either on or off), it could be tuned for optimum efficiency. In those days before microprocessor ICE control, the varying load and speed in most ICEVs really hurt efficiency. However, in the real world, parallel hybrids (without the conversion losses) usually topped series hybrids in efficiency. This is even more true today, with sophisticated microprocessor ICE control we didn't have in the 1960s and 1970s. (This might explain why GM quietly abandoned the idea of a SH Volt to make it a PH.) An interesting variant of the series hybrid is one in which the APU (auxiliary power unit) is a fuel cell. I don't know how it does in efficiency, compared to other hybrid designs. You could also argue that e-bikes are human-electric parallel hybrids. FWIW, the plug-in Prius has elements of both a series and parallel hybrid. >From what I understand of the Volt, it does too. Back to the point. In the late 1990s and early 2000s, Toyota and Honda (and a few other automakers) co-opted this "greenish" word - "hybrid" for vehicles that ran solely on petroleum fuel. This blurred the word's meaning. I can't speak for everyone born soon enough to remember the work done with actual hybrids in the 1960s and 1970s, but I for one get pretty annoyed at this. I consider it a form of "greenwashing." I admit, mIne is a pretty lonely campaign ;-), but I call the Prius and Insight electrically-supercharged ICEVs. I think that's pretty descriptive of what their drive systems do, and of how they attain high fuel efficiency. I don't consider them true hybrids, and refuse to call them that. OTOH, the plug-in Prius >is< a true hybrid, if a pretty feeble one. So my suggestion (which probably very few people are going to adopt) is that the non-plugin Prius should be called an electrically-supercharged ICEV. That's not very convenient, though, and not something that works too well for ad copy. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to "evpost" and "etpost" addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
