I run an Inline thermostat from improved racing I believe is the company. It's a 145f thermostat, it warns my trans up alot quicker. I haven't ran it in the summer yet. I dont see why trans temps need to be that high, if it shifts fine, has the right amount of fluid when warm and gets hot enough to build off moisture, what would be the problem with lower temps?

 

The main problem is that it wouldn't be warm enough to build off moisture.