Everything I've read shows this to be an old wives tail. While "true" that the coolant has less time in the radiator to dissipate the heat, it also has less time in the engine to absorb that heat.
X2. Everything I've learned about heat exchange says this is wrong.
What I've seen indicates that the root of the problem might be OTHER than "too much flow" IE things like bypassing internally in the pump clearance. There was a webpage investigating tightening up pump clearance and actually testing pumps for more flow.
