Drove my shutterless truck almost 250 miles yesterday. Where I live is in the foothills, meaning, rolling hills with some pretty steep ones involved.
We drove up the mountains to western Va, with part of the trip on a pretty steep 2 lane road. The rest was mostly up and down interstate. Speeds of 75+ up and around 72 back, except for the two lane, where 35 - 45 was mostly the max.
On the steepest hill at lower speeds, I never saw above 205 deg water temp, and that was only for a few seconds before the temp started falling. Usual temp on the interstate was ranging 194 - 198, with the oil temp mostly keeping steady at 4 to 5 degrees lower than the water.
The engine still warms up quickly, not quite as quickly as before, but still quite fast.
I used manual mode, and changed gears as I saw fit. I just wish I could make the engine hold in gear longer before it downshifts. Shifts down way too early for my liking, even with very light throttle.
Fuel mileage on the meter was an even 24 when we got home. When I have hand calculated, the meter always shows abour 3/4 mile per gallon low, so I'm happy with that.
As for the shutters, I will never put them back. Steady water and oil temps without fast swings up and down is much better for the engine in my opinion. With steady climbs and falls, everything expands and contracts at the same rate.
Ram's objective is to make the EPA happy, and try to keep the engine alive past warranty, then you are on your own.