The nomenclature has become confused because GM has introduced the E-REV moniker unnecessarily. The Volt is a series plug-in hybrid vehicle (PHV, the electric is really superfluous, so I don’t include it like most people). GM has tried to assert that PHVs don’t have all-electric capability, but there is nothing to support this assertion. GM wants the Volt to be treated like an EV by the EPA in their mileage assessment, and that is why they have muddied the waters with the E-REV term. But just to be clear: PHVs can and do have full all-electric capabilities, and so you can call the Volt and the Fisker Karma series PHVs.