I had always thought the Volt <i>was</i> a series hybrid, but I just checked [0] and it turns out there&#x27;s a mechanical bypass mechanism that can connect the gasoline motor to the drivetrain, under control of the engine computer.  Sounds like at low speeds it operates as a series hybrid, but at highway speeds, once the batteries are drained, it turns into a parallel hybrid.  Clever!<p>EDITED to add: dwhall posted a link with much more detail [1] -- very interesting!<p>[0] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Chevrolet_Volt#Drivetrain" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Chevrolet_Volt#Drivetrain</a><p>[1] <a href="http:&#x2F;&#x2F;gm-volt.com&#x2F;2015&#x2F;02&#x2F;20&#x2F;gen-2-volt-transmission-operating-modes-explained&#x2F;" rel="nofollow">http:&#x2F;&#x2F;gm-volt.com&#x2F;2015&#x2F;02&#x2F;20&#x2F;gen-2-volt-transmission-operat...</a>