Has anyone used stuff like Royal Purple's Purple Ice or Red Lines Wetter Water. Says as much as 30 degree drop in temperature? I understand what they are supposed to do but do they really make a noticable difference in temperature drop? :beer:

Works just a little. If your truck is just a few degrees hotter than you'd like, it'll help. My truck is getting 20 degrees hotter than I want it (With Redline Water Wetter), so more airflow/bigger radiator are the only effective things to do.

redline made about 10 degs. diff on my rig

i got about a 10 degree drop too

Just use a spoonfull of Dishsoap. There was a thread on it a bit ago. The dishsoap worked just as good as anything else.