My 2017 5.0 is running 217* on the highway not towing in 49* weather. Seems hot to me. What temps are you seeing. I feel like this should be around 195-205

 

My 2017 (3.5L) runs at 205* while towing in the summer. A year ago I saw some temp creep, so I changed to yellow coolant and new thermostat, fixed it correctly. All good now.

 

Sounds a bit high for unloaded highway speeds, what is the service history like for the cooling system?

I think my usual highway cruising is around 198*.

 

This time of year I'm running 194-198. I've never been over 213 even in 115 ambient temps in summer.

 

Truck has 83000 miles. I bought it a year ago. Not sure about the cooling system history but based on what you all are seeing I think I’m going to change the thermostat and flush the system and see what happens

 

Keep in mind some aftermarket thermostats don’t seem to have the best reputation for being as advertised. I think the consensus is genuine Motorcraft units are the way to go.