Usually at higher speeds & higher RPM = more heat, but WAY to many variables to consider from are you in a hot climate, climbing a grade, cruising along in heavy traffic, and so on.

Also the amount of air flow passing thru your radiator will vary depending on your configuration = ARB Bumper, a winch, or stock setup.

 

Setup for the front is a stock bumper + OEM brush guard, and a mount of RI LED pods, not big enough in my mind to make a huge difference but who knows -

These temps are around mid-80's F ambient temperature, level grade, no traffic and sustained 65 - 70 mph (or around 2,500 rpm).

 

i should have been more clear. both my '04's run hotter on at highway speeds when the temp is in the 90's and the A/C is on than they do in stop and go.

highway speeds mean 70-80 mph.

they both run in the 180's to 190's when the A/C is off at highway speeds.

one '04 is stock. the other has bigger tires, diff guards and a heavy winch bumper on the front.

 

My 04 runs warmer on the highway only in 80+ degree weather. It did with the old engine and the new Turner engine with cam. All new cooling system as well. 2004's have no oil cooler. I'm sure that accounts for more heat at higher loads.

 

All good responses - So if I'm sitting around 204f - 207f on the highway, through a 7+ hour road trip: Should I be worried or not? No idea if I'm causing any sort of pre-mature wear here running at the temp for long periods, or if that's just part of the design.

 

As designed these were supposed to run at 220 so no, 207 is nothing to worry about. With more bleeding you should be able to drop it under 200 though.

 

I was wondering that -> My temps did drop a few degrees after switching from a 50/50 ratio to 60/40 water to coolant, I can try upping the ratio and bleeding more and see what effect it has. Thanks!

 

I would suggest opening the bleed screw first thing in the morning with the engine stone cold. If there is room to add even an ounce of coolant in there, then you can displace some air there... pinch the edge of a paper coffee cup into a V and fill to the top and replace the screw. Repeat each morning until there is no longer room to add coolant that way.

 

 

Yup, same here. This time of year my ‘04 idles in town traffic at 189>194. I occasionally see 196, and very rarely 198 for a second of two. The highest I ever see on the hwy is 194 for a blip. It is in the 180’s 95% of the time.