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Old 11-29-2010, 05:49 AM   #26 (permalink)
tumnasgt
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Join Date: Feb 2010
Location: Wellington, NZ
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The Charger - '15 BMW i3
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Quote:
Originally Posted by roflwaffle View Post
The latter is how the Volt works more or less IIRC. Instead of just having one discrete state they have more than one depending on how much power the motor needs. There is a slight efficiency increase by only operating the Volt at whatever different states, but it's small compared to the drop in efficiency from generating efficiency to feed to the motor instead of just going from the engine to the wheels.
I suspect that having direct drive instead of the transmission would more than make up for the loss. Fixed output generators are much more efficient than variable output as they run at the most efficient speed. An hybrid car is a perfect application for it as the alternator can be set up to load the system at its most efficient level. As I understand it, the Volt only provides the amount of electricity needed to power the wheels + a bit extra in case of steep hills, so it cannot always be running the gasoline engine at peak efficiency.

Regardless of which is actually better, I agree that GM made the wrong decision. Of the two sensible solutions (true series hybrid or Prius-like hybrid), they managed to combine the worst bits (having a transmission and going gasoline -> rotation -> electric -> rotation).
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