On Mon, 14 Nov 2011 13:31:24 +0000 (UTC), Jules Richardson
wrote:

On Mon, 14 Nov 2011 03:52:03 -0800, bob haller wrote:
generators running on natural gas produce about 20% less power than on
gasoline.

AFAIK, that's a worst-case for after-market conversions with poor
airflow. Best-case is about a 4% loss, and real-world typically ends up
being somewhere between the two (but I think CNG usually reduces
efficiency more than LPG does).

No, that large drop is from the lower amount of BTUs put out by the
other fuels in comparison to gasoline. Gas has noticeably more power.
Propane puts out 74% as much energy as gasoline, diesel more than gas.
http://www.propanecarbs.com/propane.html See the chart labeled
"Comparison of Fuel Properties"

Oh, whoever posted that other link yesterday to kits for conversion
should know that the website is dead and their 800 phone is off.

--
That's the thing about needs. Sometimes, when you get them met,
you don't need them anymore. -- Michael Patrick King