I thought I'd update the thread with some data regarding effectiveness and cold weather.
It's currently 38 degrees outside, the coolant temperature was 197 degrees before getting on the local 4 lane road and according to my log the coolant temperature had dropped to 148 degrees within 1.5 miles going 55-75mph. /ubbthreads/images/graemlins/shocked.gif
It looks like I have a thermostat to replace.