tried it in several vehicles since the late 70s and over 3 decades. In street cars, street/strip cars and race cars, with 50/50 anti freeze and with straight water. Never saw a reduction in operating temperture in any of them. I'm long over donating my $ to redline. Today, my race cars run straight water and my passenger vehicles a 50/50 mix of antifreeze and water. None have have waterwetter in the cooling system.
http://www.thetruthaboutcars.com/200...%C2%AE-review/