Further analysis of the gas mileage situation yielded some new clues as to the
source of the problem.  First off, the oil does seem diluted and less viscous,
although not having an overpowering fuel smell.  Second, the spark plugs are
black!  Third, two of the fuel injectors are dumping fuel instead of spraying
fuel.  As well, the injectors are dirty!  And the air filter is a piece of
crap.  The date on it is 1996, so it definately needs to be changed!

So, my questions to everyone are:
1.  Do I clean the injectors by running something through the fuel system?  If
so, what additive to my fuel will do the trick?  If not, what can I use to
clean them if I have to remove them?

2.  The plugs are black, but the spacing seems to be fine between and they are
fairly new.  Should I replace these as well?

3.  Should I change the oil before or after cleaning the fuel injectors?  I was
going to change it anyways with Mobil 1 20W50.

4.  Is there anything else that I should be thinking of?

I checked the fuel system for leaks, and there are none that I can see.  It
seems that there is a lot of unburnt fuel, and excessive amounts of fuel being
dumped into the cylinders.  If anyone has any more ideas, I would greatly
appreciate your insight.

Thanks again to everyone,
Ryan