Another thing to keep in mind re: injectors or O2 sensor, the O2 sensor is
not used by the ECU at idle.  This is why the CO adjustment on the AFM is
used.

So really the calculations using the volume are pretty close.  This would
of course apply to a warmed up engine though, since a cold engine uses
something like twice as much fuel.

Years ago, I read an article about a test VW did in Holland (I think it
was) where they fit some Golfs with Diesel engines that would
automatically shut off at idle and automatically restart when needed.  The
finding was that they were off about half the time.  This could save some
emissions over time for sure.

Ciao,
Gregory Smith
Olympia, WA
'84 Vanagon