What is a good coolant

[Brock]

I never pay enough attention to the coolant. I mix and match whatever cheap cap I can find and have never had any problem that would lead me to believe I should change this approach, it's coolant.... not oil.

I've never tested my coolant as in2trux suggested although I like the idea. A rad shop owner once told me I should test the silica level from time to time but I really didn't ask how nor did I care. extended life has a wicked life expectancy and I just change it usually once a year, sometimes I stretch it. I don't believe any fluid is meant to be left in for that amount of time...

Now I'm thinking I wanna test the pH