5W-30 does not belong in a Mercedes diesel engine. Also all M1 synthetics are at least CF rated which is perfectly good enough for light-duty diesels like ours (at least the older ones), but only some of these oils are of the right viscosity.

__________________
2004 VW Jetta TDI (manual)

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