The question to use stats, or not use them has been debated over and over for the past sixty years.. The common consensus is: Use, don't use.. The wide variation of opinions pertaining to the use of stats is mostly based on very old habits that have been passed down from father to son, i.e. older generations.
The basis for these opinions are based on two beliefs:
1.. That stats are only needed for winter driving to warm the coolant/engine up so the heater will work.
2.. The anti-freeze of the early thirty's/forty's was generally an alcohol based product. Alcohol boils at 180 degrees, therefor it was a common practice to drain the alcohol based anti-freeze and remove the stats in the spring, re-installing them in the fall.
When I went through an auto mechanics school in the early 1950's, the phase covering engine cooling systems stressed the importance of stats to maintain an optimum operating temp of 180 degrees, winter or summer.
The problems of not running stats, to maintain a constant temp is that variations in the operating temp can cause excessive swings in the engine temp/coolant, rising on the up grade of a hill, and falling to very low temps on the down hill. These temp swings can lead to cracked blocks/heads..
Modern engineering has raised the average operational engine temp to 195/200, yet I know several people that put 140/160 degree stats in their modern engines because they think the engineers/factory's don't know what they are talking about.
Ford, as well as most of the manufactures of the '30's and later, shipped their cars from the factory with thermostats, that should pretty well sum up the whole subject.
