What about propane? Can your generator run on either?
   In Korea lots of cars run on LPG which I here is mostly
   butane.

   Jeff Martain



The kits can be had in a multi-fuel set-up. I would use propane if I had
to take the gen to another location, but with NG plumbed right to the
house, it is a no brainer. Propane is a bit more expensive to run I
think, but not as high as gasolene.
In hunting it down, i spotted a guy who sells conversions for autos.

http://www.hendrixsystems.com/index.htm

C. Smith