Greetings,
 
Since I seem to have plenty of cooling capacity, I'm thinking that it may be time to add some coolant to my distilled water.  Since I live in Florida, I don't need all that much freeze protection, so I'm doing it mostly for the corrosion protection, and pump lubrication.  My goal would be to use as little coolant as possible, to get freeze protection down to maybe 20 degrees.  Less coolant also means better heat transfer, which is another reason to use as little as possible.
 
I could swear that I've seen a chart that tells the percentage of coolant vs freeze level, but now I can't find such a chart.  On the manufacturers pages, they seem to want you to stay between 50 and 70 percent coolant.  I never saw them recommend less than 50%, and one page even said that you needed at least 50% for corrosion protection.  I could certainly run distilled water, and water wetter in the summer, and 50/50 mix in the winter, but I'd like to find one mixture that would work year round, just in case I ever manage to go more than a month or so without having to drain the water for some reason.  Hey, it could happen  Anyway, the real question is- what is the minimum percentage of coolant that will protect down to 20 degrees, and will this provide all the corrosion protection, and lubrication that the engine needs?
 
Thanks,
Rusty (Southbound in 5 days)