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Old 05-22-2017, 10:00 PM   #53 (permalink)
California98Civic
Cyborg ECU
 
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Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299

Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 66.42 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
Thanks: 2,373
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Quote:
Originally Posted by oldtamiyaphile View Post
The answer is simple they assume a gas/brake driver. For a hypermiler extra weight is just stored momentum, it's like a hybrid but with 100% efficient energy conversion.
It is a good point. But it applies less in typical conditions than we might assume. If we are in perfect hypermiling conditions on a track and can completely coast down to stop without traffic interruptions, then the gain and loss would I guess be equal like you suggest. But most driving is not even close to track conditions--especially non-freeway driving. We have to use brakes sometimes. We also have to start from a stop on a hill sometimes. Additionally, some rotational mass savings are MORE effective for hypermilers who use the P&G technique. For example, a lighter flywheel or lighter accessory pulleys waste all their momentum when a driver cuts the engine at speed and shifts into neutral to glide. On the next pulse, that mass has to be spun up again--only to be entirely wasted on the next glide a few seconds later.
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See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.



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