I don't think that the temperature gauges fitted in most cars are exactly precision instruments.

They're fitted because customers say they want them, but they're not really giving very much more information than the warning lights that some makers use (blue for cold engine, red for overheating, no news is good news).

I'd still rather have one, so that I have some idea of the water temperature. Usually, when the overheating light comes on it's too late, especially modern engines with their tiny coolant capacities.

I've driven cars without a gauge and felt blind without one, like forgetting ones watch.

Edited by corax on 20/01/2015 at 07:53

I've had 4 VW group cars and all have the temp gauge settle once warm in a perfect vertical at 90 degrees C regardless of conditions, speed anything. Not sure how accurate it is but it looks good!