OK Stefan, let's go take the "rhetoric" item by item....................
"I agree with the above commentary that suggests the 160 degree thermostat is ineffectual. It would be nearly impossible to perform a controlled experiment that demonstrates that it is effective as there are too many variables that cannot be controlled. I think everyone is in agreement that it won't prevent your car from overheating as the stock thermostat opens fully before that happens."
We employed commercially available data loggers, which were left in the test cars for periods ranging from five days to two weeks in order to observe how the vehicle's baseline temperatures responded in "real world" driving conditions. And, no one ever implied that a cooler thermostat was going to prevent a vehicle from overheating; only that it would run at a cooler baseline temperature, which it does when using the 160F stat.....................
"The rhetoric that suggests the stock thermostat doesn't actually open when it is supposed to is based on similarly uncontrolled experiments, whose results are worse than incorrect, they are misleading."
Not really true. To collect information on when the stats begin to open and are fully open, we employed a laboratory magnetic stirring hot plate and four liter glass beaker for our bench tests. The hot plate has a calibrated rheostat to control the rate of heating, and an independent speed controller for the stirrer to assure constant water movement. The test thermostats (all brand new) were all suspended midway down by a wire to prevent any uneven heating effects. Each type of thermostat was tested four times, and allowed to cool to ambient temperature before subsequent tests. Each test was begun with fresh tap water that exhibited a temperature of 52-54F (measured by a digital read out thermometer with its sensor tip at the depth of the middle of the thermostat in the beaker). The stirrer was turned up to a setting of "50", and the heat was then turned on with the rheostat set to "60% power". Temperatures were observed when the thermostat first began to open, noted as a gap appearing between the center plunger section and the outer housing, and when the center plunger stopped moving and was fully open. Because of the experimental design, the rate of temperature rise allowed multiple observers to independently note the start and cessation of plunger movement, as well as the temperatures. These observations agreed within 1-2 degrees. The results are as previously summarized in early posts.......................
"Additionally, note that the 160 degree thermostat makes the car take longer to warm up which decreases fuel economy and increases emissions."
Interestingly, as far as warm up, just the opposite seems to occur. The M96 is factory equipped with some coolant by-pass flow capability, which helps provide of heater output well before the thermostat actually starts to open. Because the 160F stat starts to open, and is fully open at a low temperatures, several owners have commented that they feel the car is warming up "more quickly", most likely a perception triggered either by warmer air coming from the heater sooner, or because they see movement in the dash gauge earlier. When the manufacture was asked about this observation, they confirmed that "It is a normal observation" for the 160F stat to be observed as warming up to running temps more quickly due to increased warm water flowing sooner. Unfortunately, because the "warm up rate" perception rests with the car owner, it has not been independently or experimentally confirmed, but has been noted by multiple owners.
As for emission, as mentioned previously, I operate in a state were "sniffer" emissions testing is common. To date, none of the cars, my own included, has demonstrated any problems passing state emissions testing. While I have only seen some of the actual test values (we are not licensed to provide emissions testing), but from what I have seen, there does not appear to be any significant change in the values (HC, CO, and NO in this state) before and after moving to the cooler stat, so there does not appear to be any detrimental impact on emissions. And, again as noted previously, owners (myself included) have observed slight (2-4MPG) increases in fuel economy durng longer trips; which have not been evaluated experimentally due to significant variances in driving styles, road types, weather differences, etc., etc
Now, if you have either experimentally sound, or even significant empirical data that supports another perspective, I for one, am always open to listening and trying to learn something new...... But, in any case, have a nice Easter..................