I run Mobil 1 Synthetic 15/50 in my '90 2.1L WBX.  It's time for an oil
change so stopped into the local Auto Zone to pick up the oil.  Normally
$7.49 a quart, five quarts, would normally be $37.45 (plus local sales tax,
just under 10%) but wait, on sale!!  If you buy five quarts AND an oil
filter only $29.95!!  But be prepared you HAVE to take the filte4r to get
the deal.  And I'm told the filter is a "$12.95 value".   I suggested that
they ring it up w/o the filter (not going to use their filter no how) but
no, I had to have the filter.  Okay, ring it up with the filter I said.
Then after paying (reciept shows a $20.45 discount) I tried to hand the guy
back the filter.  No way, hea really wantd me to have the filter.  So, I
saved about $7.00 on the oil and now have a filter I'll never use. I'll take
a look at it later and see what it looks like.