My original question was referring to the amount of time and/or miles it takes for your motor to reach a FULL operating temp or around 195 degrees. On the factory Ford gauge this is approx 1/3 or so up the coolant gauge. By that time, the heat should be blowing HOT, oil temperature (for those that have an oil temp gauge like I do) is also within 10 degrees of the coolant temp of around 195. What I have inferred from some of the descriptions is that on cold days (30 degrees or so) this marker does take several miles of driving and at least 10 to 15 minutes of drive time to reach.