Been running T6 diesel oil in my 300E for about 33k, no oxygen sensor issues. My dad has been running it in his 420SEL for over 15k, no issues there either, runs great.

As my 420 is only a warm weather/seasonal car, I run mobil 1 15w50 in it.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)