These products were originally formulated for track use, where glycol anti-freeze is usually banned as a coolant because of the non-drying slick it leaves when spilled.
It's likely that the primary active component is corrosion inhibitors and something to lubricate the water pump seal, but you aren't promised that. The actual wetting agent is insignificant in both the proportion and cost. It takes less than a drop of wetting agent to treat two gallons of water.
My belief is that this product has changed from being a useful specialty additive, to something that is misleadingly marketed to extract money from the gullible. The traditional anti-freeze+water mixture is the best coolant for a street car. It provides the best protection against destructive overheating.
Sure, when you run when you run a test with the same volume and temperature of water vs antifreeze running through a radiator, the plain water transfer more BTUs because of its higher specific heat. But change it to running the fluids at their *boiling point* and the antifreeze mixture has a huge advantage. And protection is about moving the heat and keeping an insulating steam layer from forming when the engine is really hot, not when it's only 220F.
Finally, the claims for better heat transfer go way beyond the small gain of the specific heat of water. I'm guessing that they are based on the heat transfer of water beading on an oiled surface vs. wetting the same surface. But
- almost all of that effect goes away when the water is under pressure and has non-laminar flow.
- most cooling systems that have been previously run with corrosion inhibitors have hydrophilic, easily wetted surfaces.