A unique electrified transaxle

Hybrid or not? Definitions aside, what really matters is GM wisely leveraged its next-generation Two Mode propulsion technology to give Volt greater overall efficiency.

Leave it to the Volt to cause the telephones at SAE International to ring almost nonstop. Since the car's media launch in early October, reporters have been looking for answers as they try to apply a standard technical description to the Volt's cleverly engineered powertrain.

GM has called it an “E-REV” (extended-range electric vehicle) ever since the concept was unveiled in January 2007. Over the course of the next 40 months, simply mentioning the word “hybrid” around any of Volt's senior development team members netted plenty of discourse as to why their baby is a new breed of propulsion system. Indeed, AEI's first story covering the original show car described Volt as a series-type plug-in hybrid, drawing fire from two ranking executives on the program.