Oh, don't know if anyone has considered incorporating one of these in their cooler set up, but I would recommend using an oil temp thermostat.
Looks like a few dynos on here suggest optimal power around 195* F, so I'd spring for the custom set one, set it for that (or 200* even -- 180* is a bit cool IMO) and then you are set for all driving conditions
BAT, Inc. - MOCAL Oil Coolers
Will probably do this for peace of mind at some point -- ensures you never run too hot or too cold
