Go with the 195/196....that is optimum. 206 is a high reading unless your towing a heavy trailer during warm temps.What is the go to method to get the trans temp up to at least 206? That is the low temp for checking the fluid level. Cannot seem to get mine past 196 or so. I'm using torque pro and the trans temp sensor to check it.
Yup...I have a Scan Gauge ll with the coolant and trans fluid temps side by side. When fully warmed up both fluid temps usually do not very from each other more than 5 degrees, usually both around 195 or so. Only time I ever had trans temp go a bit past 210 was towing thru No.Carolina and Tenn up mountain grades for several miles. Coolant temp was about 10 degrees lower, but both came back down quickly upon cresting.Yes, this is one of those times the manual can be - WTH, as the purpose of the Trans Fluid Cooler is to cool the transmission fluid down to (Engine Coolant Temp)
It also heats the transmission fluid up (when starting from cold engine)
So, unless you are under heavy load the transmission fluid will maintain - engine coolant temp.
Guess your right about 4th gear.You can get it to the 205-210 range in warmer temps (65-80f) by driving on the expressway for about 10-15 miles in 4th gear and about 4000 rpm. It equates to around 70mph. I have done it multiple times after I installed the Fitzstick.