MB chose not to damp the temp response in the gage. As a result, you see the temp gage moving around at a greater rate than other cars.

It's normal to see it rise from cold position to it's normal position and it should remain fairly stable under steady state, flat driving. It's normal to see a rise when climbing a hill or while stopped and idling.

Jim

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14 E250 BlueTEC black. 45k miles
95 E320 Cabriolet Emerald green 66k miles
94 E320 Cabriolet Emerald green 152k miles
85 300TD 4 spd man, euro bumpers and lights, 15" Pentas dark blue 274k miles