Red Line Water Wetter provides corrosion and rust protection for modern aluminum and cast iron cooling systems. A unique additive reduces coolant temperatures by as much as 30 degrees F. This additive can be used in plain water, to provide much better heat transfer properties and protection than glycol-based antifreeze, or can be added to new or used antifreeze to fortify inhibitors and reduce foaming.
Redline Water Wetter is a great additive to lower engine temperatures. I use this in combination with coolant and distilled water (since i live in UT where it gets a bit nippy in winter) and it has worked out great for me so far. The only draw back (more of an inconvenience really) is that in winter the car doesn't get up to temperature on 15 or so minute drives, but I also have a high pressure radiator cap that affects warm up time as well.
Other than that I highly recommend this product!
prometheusecks reviewed Redline Water Wetter part # RED-80204