The Gen 2 Voltec drivetrain has two motor&#x2F;generators, two planetary gearsets, an abundance of clutches and the ICE.  This allows the system to be used in five distinct drive modes ( <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> ).  The all-electric range increase is proportionally greater than the battery capacity increase because the new drive system uses two-motor drive mode more often than the first gen drive system.