Do you know what year/application they started using the three wire coolant temp sensors? I have wondered for quite some time why they went to three wire oil pressure senders/switches but kept the separate CTS/gauge sender for coolant. Apparently they did at some point. I hadn't run across a three wire coolant device, or I would have swapped mine already!

Another possible "feature" would be if it were possible to trigger a "check engine" light with a low or high temperature reading...could use the temp sender as a low oil/hot oil warning as well, if it were placed in the pan in a location that was normally well immersed in oil with the engine running.