Here are two (coldest and hottest) readings for my transmission.....

January 18, 2013, 29*:
- Coolant @ 183*
- Trans @ 145*


August 29, 2012, 70*:
- Coolant @ 206*
- Trans @ 194*


The car drives so much nicer right now, with the cooler running tranny. My drive to and from work is 30-40 minutes and 90% highway (cruising at 50-60mph). If I head for the hills or a long trip, she's gonna get real hot and not be happy with a 4-6 hour windy/twisty/uppy/downy highway day. A trans cooler is a must in these scenarios.