mbsteve: With WaterWetter, you add one bottle ($8) to your rad and reduce the coolant to water ratio to about 20%, depending on the temperatures you are expecting. This should be good for a 10-12 degree reduction in coolant temperature. More coolant in the water means less temp reduction.
BE CAREFUL you maintain enough coolant to prevent freezing! Obviously, WaterWetter is not a year-round solution if you live in colder climates.
"Lead, follow, or better yet, get out of the way!"E500 owners motto