I last changed my oil in May and have put on only 2,400 miles since
then.  How important is the time factor in oil change frequency?  Does
oil go bad over time even when the van is not being used that much?  The
3,000 miles or 3-month (whichever comes first) rule-of-thumb seems to
imply that it does.  I use Mobil 1.

Gerry
'87 Westy