When I got my 87 300D the temp display was no good, I had a parts car (95) so I swapped in the display. It works but is always off by 10 degrees. My 87 was in Fahrenheit but the one I replaced it with is in Celsius (my preference). Everything I have read says they are interchangeable but I’m not so sure. Is the probe outside the same or is that the source of my problem? Or could the display simply be bad? Anyone have this issue?

__________________
1987 300 TDT
1990 300 SEL

In 95, the computer had an algorithm to be more accurate with road conditions etc.
So yours is likely calibrated for that offset.

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!