At 07:38 PM 12/4/2010, David Beierl wrote...
>  unless gasoline
>behaves differently than it used to (and it might -- it's more of a
>mixture of heavy and light components than when I was young) you can
>spray it on a hot exhaust pipe without it catching fire* (whereas of
>course a small spark will ignite gasoline vapor).  Oil, OTOH, dropped
>on a hot exhaust will burn.

Do you have a source for that? Common sense says it's wrong, and
according to this web site:
http://www.tcforensic.com.au/docs/article10.html#1.1 , the ignition
temperature of gasoline is lower than that of motor oil (257C vs.
260++). Gasoline is also much more volatile, making explosive
combustion more likely.