Ambient Temp. and 2009 Hemi Ram

[lross78550]

Its usually about 85 degrees where I live this time of year. We get cold fronts move thru and the temp drops to the 60's. I'm a pilot so i understand the density altitude and how warmer air affects horsepower. What I dont understand is the HUGE difference that 20 to 25 degrees seems to make on these 09 dodge trucks. I live at sea level btw. At 60-65 degrees the truck screams. It feels like I'm driving a completely different truck. Could there be something wrong with my tune that would make this big a difference? Is something else at work here?
Thanks
Lee

[mikel]

Much of the timing tables are based on ambient temp, as temp rises, less timing is commanded.