On Wed, 17 Jun 1998 12:23:52 -0400 you said:
>Looking through the VW Vanagon Maintenance booklet I was surprised to see
>that VW recommends changing oil at every 7500 miles and changing the oil
>filter at every 15000 miles.  All mechanics that service cars say that oil
>should be changed every 3500 miles together with the oil filter.  Is this
>simply providing more work for the mechanics or can the oil really work OK
>up to 7500 miles?

read a little closer and somewhat between-the-lines. :) "Under severe
conditions, the oil and filter should be changed more frequently ..."
or words to that effect, somewhere else in the Owner's Manual. trouble is,
guess what city driving is??? yup. Severe Conditions.

IF you drove 7500 miles on the interstate at highway speeds, THEN you would
be safe in changing the oil and filter only every 7500 miles. but i don't
know many people who do that. i certainly don't. stop-and-go driving is the
worst thing you can do to a car, especially in winter. so the old saw about
changing the oil and filter every 3000 miles still holds true.

one rule of thumb says change it every three months in the summer (two
months in the winter) or 3000 miles, whichever comes first.

joel