IMO, running a cooler thermostat to keep a engine from overheating is an OLD WIVES TALE! The thermostat sets the minimum temperature and once it opens it also restricts the water flow through the engine.
The engine / oil are designed to run at ~ 200-210 degrees, the faster it gets there the better for the engine.
Its especially a bad idea in a cold climate.
It might produce a small amount of increased power at the expense on increased engine ware rate.
For the money, the larger transmission cooler is a better investment.
you can have whatever opinion that you want. I speak from actual real-life, real-world experience.
I've got the bigger trans cooler, the bigger radiator, etc, etc.
2 runs ago ( and granted the ambient was as high as 125 degrees), I hit 250 degrees.
Without the 170 degree thermostat, I was running 215-220 on the highway.
once I swapped it and finally got all the air bled out of the system post-swap, I didn't go any higher than 214 in the desert (100-degree ambient).
many trucks that had way smaller tires and significantly less weight in them that were still running the stock tstat had overheating issues. ( in particular, any trucks running lights above the main hoop of the front bumper.)
and another thing to mention is that if the motor is running cooler, the computer will pull less timing. This is especially relevant when down in Mexico.
When the gas is of lesser quality, the motor will pull timing and run hotter. Doing everything that you can to mitigate this is absolutely a smart thing to do.
I am also currently researching a fan swap as I think with spal fans, I can get an extra 1500 cfm of airflow.
I used to have doubts about the 170 degree tstats. Guess what? I tried it, collected data points and they actually make a material difference.
So believe me or not, but I'm usually the guy fixing other people's trucks ( or at least helping to fix them) on the runs to Baja that I participate in, so what the hell would I know.
oh and lastly, as far as "wear rate", the only way that would come into play would be if you were running an oil with different sheer properties than what the factory recommends. If anything, people tend to run thinner oil, not thicker. Don't believe me? go buy a quart of RGO, then dump it on some metal and leave it outside.
go back a couple of days later and see if you get oil on your fingers when you touch it.
now you understand that when the motor is shut down, oil stays on the metal parts. Cold starts are not "dry starts", even if you have ZERO oil in the pan. In your hypothetical, for there to be additional wear, the oil pump would need to fail, or you'd have to be revving the **** out of it immediately.
