What type of motor oil should I use for a 2001 jetta tdi?

There's a few that you can use - but in general

Use Full Synthetic only for the TDIs...

There's various schools of thought after that in terms of 5x 30, 5w 40, even 0w 30 or 0w40

I've been using Castrol Synthetic 5w 30. The original specs for my 2000 Jetta TDI may have been for 5w40 oil formulated for diesels - but with the Synthetics now I think the 5w30 is felt to be the best in terms of what works best in the Turbo

You can probably go every 5,000 to 7,500 miles between changes - a good thing since the synthetic oils are more expensive

by the way, some also suggest changing the fuel filter at every oil change. I'm thinking that's a bit much but others may disagree... maybe ever 15,000 miles for me