Like Camel Landy, I had temps spiking years ago causing me coniptions !
Once was in a heavy shower of rain on a hot day crossing the range here, the temps went to the max with the stock gauge, it wasn't until I turned the wipers off that they went back to 'normal'.
That was enough for me and crook earths, I just ordered a mechanical gauge the next day and that was probably 8 or 9 years ago.
Problem solved.

