I looked in my 2004 A4 1.8T owner's manual, and it says oil must meet one of:
1. ACEA A2 or A3
2. API SJ
It further states that 0w30 was factory fill and suitable for all temperature ranges, and that 5w30 and 5W-40 are acceptable substitutes if 0w30 is not available.
Note that this has since been superseded by TSBs and a class action suit that require a VW 502.00 approved oil in addition to those criteria, and they even sent all the owners a sticker to put under the hood saying "VW 502.00 oil only."
1. ACEA A2 or A3
2. API SJ
It further states that 0w30 was factory fill and suitable for all temperature ranges, and that 5w30 and 5W-40 are acceptable substitutes if 0w30 is not available.
Note that this has since been superseded by TSBs and a class action suit that require a VW 502.00 approved oil in addition to those criteria, and they even sent all the owners a sticker to put under the hood saying "VW 502.00 oil only."