Join Date: Jul 2008
Location: Mid-Atlantic USA
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Originally Posted by EvilV
But is that the trade off that is made. I don't see there really being a continuum with efficiency at one end and reliability at the other. I don't think these variables are even remotely related. In fact although I am far from being an engineer and am only a bodging dabbler, I feel sure that there are two quite different variables here and that the continuums (plural?) range from reliability -> unreliability and a quite separate one of efficiency -> inefficiency. I'm pretty tired just now so maybe I missed something here.
I don't know the answer either, but have been led to think maximum efficiency calls for precision whereas maximum reliability demands greater tolerances. Which isn't to say you can't have both, only that it's more expensive to achieve both. This belief comes from pieces I've read over the years offering broad-brush comparsions of the differences in engineering philosophy between German cars (e.g. VW, Porsche, Audi, BMW) and Japanese cars (Toyota, Nissan, Lexus, Acura). The common thread of these articles was that the precision engineered German cars require frequent adjustment to remain at peak performance and to avoid excess wear, whereas the greater tolerances built into Japanese cars require far less frequent adjustment and the components last much longer. I'm just repeating what I read long ago ... with the caveat that these articles were not in scientific journals but in periodicals.
P.S. If those anecdotes have a grain of truth, then I will take the slop if the tradeoff is only a slight drop in efficiency and a large gain in reliability. I hope the Alfine is the Toyota Camry of IGHs.
Last edited by timo888; 08-26-08 at 06:39 AM.