Hello to dfndr and all.
NOTE: the temperature gauge measures COOLANT temperature. It does not indicate OIL temperature. Oil will, and as you saw in the graph, SHOULD run hotter than coolant. The 100C-140C oil temperature is what boils off any water from condensation in the oil.
'96 E300D 60k mi (wife's daily ride)
'95 Audi 90 120k mi
'92 GMC Suburban 139k mi
'85 300SD 234k mi (my daily ride)