^yeah true. But isn't it that even the conventional temp meter once the hand raises above the normal level it's already a sign of an overheating engine?

That's what I experience in my old Nissan California and my dad's Galant Super Saloon. My dad's car though has a few minutes of leeway before it shoots up to the top but as far as I know even if it's pointer is not in the normal position that's already a sign of an engine overheat.