NEXT BIG THING

RANGE EXTENDERS

- WORDS: PAUL HORRELL

A RANGE EXTENDER (REX) IS A SIMPLER form of plug in hybrid. The engine can't power the wheels, but drives a generator that sends its electricity to the battery, or to the drive motor if it's needed there. Mostly you run with the battery, with the engine sparking up only when it's flat.

These things had their moment in the sun a decade ago, with the Fisker Karma, Chevy Volt and BMW i3 REX. Then we thought they'd gone. They ran well as EVs but felt odd with the engine on.