For an additional data point, at any temperature under 90F or so, my engine temp stays at 82C. At anything above 70mph, it’ll sit at around 85C. Under full load, going up an extended grade, it’ll creep up to about 90C, but no further.

For temps above 90F, in and around town, 82-85C. Highway above 65mph, 90-95C. With A/C or extended grade, 95-105C.

Was recently on a 9 hour journey from north to south CA. Average temp outside was about 98F. I drove about 70mph, with AC on max. Engine temp was at 100 the entire time.

__________________
1981 240D 4sp manual. Ivory White.