Thanks to those that have replied. Maybe I need to move this to 2009-14 section? I know there are others that if you don't mind please chime in on this topic and why ? Thanks in advance!:thumbsup:

I'm pretty sure the vast majority are running performance tunes with the stock thermostat....

Are these your coolant temps on the X4? and was the 195*-205* tuned stock thermostat? I am seeing up to 215 on my coolant temps idling, 190* stock t-stat. 90 degrees outside with humidity.

Yes those are temps on livewire device. Mine would get up to 210*+ at times idling. Not after t-stat and re-tune though

2014 F150 5.0 with an MPT 93 octane performance/street tune and the stock thermostat. Temps hover around 201-206 degrees. Last summer I towed a completely full (floor to ceiling) 6X12 U-haul trailer with an MPT 91 p/s tune and 211 was the highest temps I saw on my SCT Livewire. 400 mile trip with half of the trip on San Angelo's crappy 91 octane Exxon gas and 93 octane Exxon gas for the rest of the trip. Yes, I towed with my performance tune. No issues with overheating/pinging and it was HOT (low 100's)!!! Also half the trip was through the Texas hill country including the Garner State Park area. Lots of hills and many 3rd gear pulls up the hills.

That is very impressive in that kind of heat. I am already past that no towing.

It took a couple of revisions to get the tune right but I think it turned out pretty good. Still I think I'd prefer it if the engine operated about 10 degrees cooler. Just seems weird that these engines run such a high temp stock.

Since you live in Texas and do a lot of towing you may be better off with a cooler thermostat and update your tunes for that. Your numbers though on a stock look better than i would have thought.

Yeah i'm pretty happy with how the temps held during that trip last year. I haven't really done enough towing to merit changing out the thermostat quite yet. Truck only has 14k miles on it. It's gonna be another hot summer so I'll definitely be keeping an eye on the temps and play it by ear. If not done sooner, I'm definitely gonna change to a lower thermostat when I do a coolant change at about 50K miles.

I am running the 5 Star 87 octane Perf/Tow 170* tunes. My coolant temp runs 183*, unloaded, pretty consistently. I towed my travel trailer (~6000#) about a month ago, but didn't monitor the coolant temps at that time. My trans temp was ~196* (cluster display), though, and I was getting about 1-1/2 mpg better towing than with the stock t-stat/ previous 87 P/T tunes. I can definitely feel a power increase with the 170* stat/tune combo. I haven't really noticed any loss in heater output and am not concerned, as winters are pretty mild here and I never run it at max anyway. I'd say, if you live in Texas, "Go for it!"