Here's what I've notice. I did a check with my refractometer to see if I'm at 50% ratio with antifree vers. water. At first check I was at 27% mixture. My 5.9 would run around 190* crusing and go over 200* on hard starts or hills. No trailer, empty. I added more antifreeze so I'm now @ 40% mixed. The motor is running slightly hotter at a cruse but seems to jump up in temp. faster under the same driving habits. It's like it's running hotter now as I get closer to the 50% mixture.

Is this normal? what is yours running at.

 

Seems normal to me. I often see 200 degrees cruising down the road in the summer time, and about 210 when hitting the hills while towing.

Did you add the correct type of coolant (HOAT)?

MikeyB

 

200-210F empty in AZ summer is normal.

210-220F loaded in AZ summer is normal.

I don't think you have anything to worry about.

Tony

 

What a relief. Thank for the info. It always makes you feel better knowing instead of guessing.