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Old 02-22-2009, 05:24 PM   #14 (permalink)
roflwaffle
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Join Date: Dec 2007
Location: Southern California
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Camryaro - '92 Toyota Camry LE V6
90 day: 31.12 mpg (US)

Red - '00 Honda Insight

Prius - '05 Toyota Prius

3 - '18 Tesla Model 3
90 day: 152.47 mpg (US)
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Quote:
Originally Posted by MetroMPG View Post
Tim: you're right, their figures don't add up. 600w production in highway use, yet they're claiming that offsets 30% of power needs. Which means the car needs 2000 watts to drive down the highway? Don't think so. Their figures need explaining.

Maybe the clue is "600 W(e)". What's (e)? I haven't seen that before.
The thing is that the output in city driving is probably a lot less due to lower average power output and a small difference in temperature. The 600W is probably max output on the highway with the average output around 100-200W.
Quote:
Originally Posted by ConnClark View Post
MetroMPG's car is so optimized he could go on a diet and loose 5 pounds and get a 10% improvement. His results in magnitude of improvement are not typical gains for an average car.
The thing is alternator energy efficiency, like ICE energy efficiency, isn't linear AFAIK, which is why we're seeing things like dual-speed alternators, and the like. If this thermoelectric system can replace lightly loaded and inefficient alternator operation, then it could very well increase fuel efficiency by ~5% since the other 5% is when the alt is more heavily loaded and more efficient. It also depends on the manufacturer's alt operating parameters, which may be more efficient for a compact car that's focusing on efficiency light a Metro or Civic CX/VX as opposed to a car that focuses more on other stuff.
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