Ask your dealer and look at the owner's manual. My bet is that they recommend the Mobil 1 0W-40, but for diesels I'm sure the CI rated 5W-40 is better. If it's not recommended and you do your own oil changes, maybe you can use it but you'll have to keep it quiet. Let us know what you find out.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL