If anyone can provide numbers to back up this thermo. assertion, bring ‘em on.
Nobody can...
MAYBE...MAYBE before the engine reaches full operating temp you might see SOMETHING, but a vehicles complete cooling system is designed for a specific overall operating temp... When a thermostat opens and everything equalizes the vehicle cooling system will reach that temp.
Lower temp thermostats are a big thing in the Corvette world(or where a few years ago at least)... I never believed in them... Other people do, although when I ask "whats your car cruise down the highway at" the answer is almost always within 5 degrees of what my car with a factory thermostat ran down the highway at.
You would gain more cooling ability by running a 25% anti-freeze, 75% water mix with a bottle of some type of coolant booster(water wetter, amsoil coolant boost, etc...) in it, although in places where you see lots of cold weather, thats not really a recommended mix and you need to change it out every 2-3 years vs. 5 years for a 50/50 mix. Some new cars are now coming with like a 40/60 mix.