Look at this document: http://www.natbiogroup.com/docs/education/lubricity%20additive%20study%20results.pdf

Scroll down to the conclusion on the last page and there you'll see that 520 microns is the maximum wear scar allowed by US law, even though 460 or less was requested by the Engine Manufacturers Association. And it's not all just about lubricity. The minimum cetane required by US law is still 40 whereas MB calls for a minimum of 45 and 50 or more is really what you want for peak performance. The conclusion that any reasonable person should draw from this is that ULSD does not fully meet the requirements of all diesel engines, including ours. Don't use additives if that's how you like it, but there's no need to create the impression that using additives at the pump is controversial, because it's not.

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2004 VW Jetta TDI (manual)

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