In my 04 GT, the highest i saw was 228. The coolant was around 210-215, outside temp was 97* and i had been in stop/go city traffic for about 90 minutes. I had been on the highway for about 6 hours before hitting the city traffic.

On the highway my winter/summer average trans temps are 145/180 city between 160 and 210 year round, again depending on how much i am demanding from the car.