Yup you're right. I had just read a thread on thermostats and had 180* on the brain. Case of thinking 1 thing and typing another.

Piet, even w/the solution raising the BP. The additive I suggested would do this also. Then you have the fact that the more water you run the better your system will cool. No need to worry about boiling over if you never get near that hot.

Either way, if your system works properly and is adequate, you should never have overheating problems. In the 12 years I had my 70 it got in the low 200s twice. Both times were from mechanical failure of part of the cooling system. Even in 110* temps sitting in traffic it would only get to 190*. I ran it 30-70 (AF-H2O) mix and it never had freezing probs even being parked outside w/temps in the teens. It wasn't stock either. This was a 12 sec street car w/ a 350, headers, th350, 10" converter and 4.11 gears and yet the cooling system was stock.

 

50/50 is the best, you can "get away" with water, but antifreeze also helps stop electrolosis (spelling?) in aluminum, and rusting in iron, if possible use distilled water in aluminum applications

 

Again, that is where the additive I mentioned comes in in pure H20 apps.

I ran my car w/the 30/70 mix for 12 years w/no adverse affects.