I was not thinking so much about the fans as I was about the coolant
temps being lower.
Look at it this way: If you have all other things equal (engine
speed, ground/air speed, grade of road) more air thru the radiator
will give you lower coolant temps.
I don't have my book with me right now but there are two temp ranges
here: Fan switch & thermostat setting. Its clear that no matter what
the ground/air speed the fan will come on when the coolant gets hot
enough. But there is a gap between when the thermostat is fully open
and when the fans come on. All other things being equal it would be
better to operate in the range when the thermostat is just coming
into full open then running just under the fan temp switch point.
