engines temperature.

I have developed a complement to GPS equipment, and is based on avoiding the overheating of the engines by means of a protection circuit that immobilizes the car before the temperature reaches the maximum level of the indicators protecting it from the eccessive heating. At the time the car blocks sends an SMS with the GPS heating alert and is restored only when returning to the proper temperature preventing it from being used by the unit and provoking more damage. Now my question is whether they have any exact temperature record in central degrees taken from the heads of the engines. I have already taken the readings of the Tsuru cars and the Ford Fiesta and the normal working temperature is 76 degrees in the two engines, the level of the maximum indicator is established in the 115 degrees, this is the indicative that the engine is already in danger, with the circuit block the car at 90 degrees that is very low from the maximum point. Does anyone have someone readings of other marks?