Like HowStuffWorks on Facebook!

How the Hüttlin Spherical Engine Works

Author's Note

This assignment initially struck me with fear: the fear of typing "range extender," combined with any word containing an umlaut, into Google. Upon further research, I discovered the inventor of the Hüttlin reportedly refers to his creation as a "kugelmotor." "Kugel," which may sound familiar to aficionados of Jewish cuisine, is actually German for "ball." Not at all reassuring. But I still had a glimmer of hope for the spherical motor. I tend to be fond of German engineering beyond all reason (such as my bizarre affection for a particular type of compressor-style supercharger, best known for its presence in late '80s and mid '90s VWs that was practically guaranteed to fail spectacularly at precisely 60,000 miles).

That said, it still took a bit of time to understand how this ball gets rolling. Every description I read seemed drastically different, borderline contradictory. And there was no shop manual handy to coax me through. So, considering my experience with German motor development, it seems a few decades have made a world of difference. (And on that note, my pulse quickened when I discovered that the Hüttlin has air-cooled potential. My fantasy future Karmann Ghia project just took on a whole new dimension.)

Related Articles


  • "Exclusive interview with Innomot about the Hüttlin-Range-Extender." April 7, 2011. (Feb. 24, 2012)
  • Innomot AG. "Hüttlin Drive Technology." (Feb. 24, 2012)
  • PRNewswire. "Range Extenders for Electric Vehicles 2011-2021." Nov. 3, 2011. (Feb. 24, 2012)
  • Rice, Vincent. "The spherical genius of the Hüttlin Kugelmotor." Gizmag. Sept. 25, 2011. (Feb. 24, 2012)
  • Vorano, Neil. "The green future at Geneva Motor Show." The National. March 5, 2011. (Feb. 24, 2012)
  • Wojdyla, Ben. "Six Prototype Engines to Get Your Brain Firing." Popular Mechanics. Feb. 13, 2011. (Feb. 24, 2012)