anyone using redline water wetter diesel in their ML cdi or bluetec? Supposed to make it warm up faster and remove hot spots on the engine head. I have used their regular water wetter it in previous gasoline cars and suvs. Any thoughts on using the diesel one in our trucks?

I have almost 70K miles on my ML and have yet to see the temp. gauge not warm up fast on its own. Also I have never seen it go over the normal mark.
I have used the water wetter in an older car I was racing at the time, but for the ML, the cooling system seems well enough designed so I would leave it factory.