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Old 12-23-2010, 08:01 PM   #17 (permalink)
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The reason P&G works is because most engines are too lightly loaded for optimal efficiency at cruise. So, yes, engines do have their peak efficiency at low RPM, high throttle conditions.

However, this just means that most ICE are drastically oversized (and overgeared) for cruising. If you have a reliable source of electric assist, you can equip the vehicle with an ICE that's just large enough to cruise with, and use the electric (which has a very flat efficiency curve) to accelerate. This is how hybrids work, and they do work.
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