oil filter replacement schedule

[Douglas Frank]

I've been replacing the filter every 10K miles like the good book says.
  Last weekend I actually bothered to read what it says on the can,
which is: "2 Jahre 30000 kms."

Kewl.  Then I can go 15k miles on a filter, easy.  Right?  Why replace
it more often?
--
Douglas Frank  DigitalWhoopsCompaqImeanHP Co.
ZKO            110 Spit Brook Rd.       The older I get,
603-884-0501   Nashua, NH USA 03062       the better I was.

'98 A4 1.8tq