TheDodgeGuy said:
I wouldn't waste my money or time on any additives such as Water Wetter or Purple Ice. They haven't proven themselves to do much, if anything, to aid in cooling system efficiency.
Applying simple physics and the rules of surface tension, both Water Wetter and Purple Ice reduce surface tension of the coolant thus allowing the bubbles to break the surface more efficiently and thus reduce heat held in the coolant.
Surface tension on the top layer of a liquid is what allows bugs to walk on water and allows small things to 'sit' on the surface of water. The water is like a sheet. When in a cooling system, this sheet prevents bubbles from breaking through and dissipation of heat. Reduce the surface tension and increase the heat loss of the cooling system.
When boiling water, if you add a drop of soap to 'hot and ready to boil' water, it instantly boils. No soap, you sit and wait for the heat to become greater than the surface tension holding back the boil. That could be a difference of minutes. The soap drop reduces the surface tension. Water Wetter type products do the same thing.
Note: Don't add soap to your coolant system. Agents like Watter Wetter are formulated to not foam and bubble. Soap foams and bubbles and would be horrible in the coolant system.
Since this thread is more about being concerned with not getting enough heat, an additive allowing for a cooler running engine may not seem appropriate. However, a cooler engine itself is more efficient and produces more power, thus an acceptable trade. If the rest of the cooling system is up to par, you'll get to temp nearly as fast (within a block or two more literally), retain running temps to maintain heating temps, produce more power and cool down quicker. For the $4 a bottle spent, it's a no-brainer actually, even if it gains you a non-noticeable percent or two of benefit.
From my experience, my D with 180 stat performs nicely with the Water Wetter and does run cooler. Watter Wetter specs 180 stats while Purple Ice, which tends to cater to more race related crowds, specs a 160 stat. That's too cool for our Ds and the PCM programs.
Wikipedia's = Surface tension. Interesting stuff.
Watter Wetter Demo. Also interesting stuff.
IndyDurango