At my request I had asked Gator to put clear water in the radiator of the T for me and I would mix up the antifreeze when I got the car home. With clear water the T ran around 205 degrees at full speed.
Being a transplanted northern boy to the south I used two gallons of antifreeze and one gallon of distilled water which brought me a freeze level of -50 below like I would had normally done up north. My wife and I took the car for a ride last night with the air temperature of 95 degrees and the car was running real hot. At one point it got all the way up to 230 degrees but would cool rather quickly back to 200 at an idol. The only thing I had done differant to the car was to add antifreeze. So today I dumped out the antifreeze into my large drop pan and remixed it to +10 degrees which I'm sure here in sunny central Florida with the car in the garage should be ok. Took the car for another ride with the air temperature of 93 degrees and the gauge only got to 202 degrees with both ears down. So I'm assuming that because of the heavy mix it was not flowing right with the hotter air going through the radiator. Now that being said that heavy mix always work well up north with a normal temperature air of around 40 to 85. It must be the difference of the air temps between the two differant climates. I'm not sure if humidity would play into any part of the equation but it is much more humid here in Florida than it would had been in northern New York.
66% anti-freeze is good to at least minus 70F. (The boiling point at sea level is approx. 240F.)
Where up north did you live to require that concentration? Seems beyond overkill to me.
I live in MInneapolis and use 50/50 in my modern car which is good to minus 35F. It never gets below minus 20F where I live.
Erik, I lived in a small town called Evans Mills, About 20 minutes from the canadian border. -50 below was a bit over kill for up there but I did see temps up there get close to -35 below. Back then I just set everything to -50 and I was able to sleep better at night.
Water has a higher specific heat than ethylene glycol and therefore is more efficient in transfering heat from the block to the radiator. Also, glycol is more viscous than water, which of course slows down thermal syphoning. Conversely, glycol has a higher coefficient of thermal expansion, which helps thermal syphoning. Add it all up and on the bottom line, your engine will run a little cooler with water. But only until the water rusts out your block or your radiator freezes solid. Back in the day, having only alcohol for antifreeze, many folks drained the water every night and filled it back up when they started the car. My dad once forgot, and cracked open a model t block. Anyway, the rust inhibitors in modern antifreeze are pretty important.
I live in Canada,what you must always remember is the wind chill factor,it will bring the temp way down
Wind chill factor only affects mammals. It does not affect anything else.
I live in California (southern). The lowest I remember it here was +18. That only happened once in my 80 years. It gets over 100 in the summer. I use one gallon green anti-freeze and fill the rest of the way with distilled water. When I need to add, I use distilled water. The only time my T has boiled was when I had a leak and the coolant level got low. I can't imagine it would get below zero in Florida!
Wind chill has nothing to do with determining the antifreeze mixture that is considered appropriate for the area where a vehicle resides.
The temperature of any object regardless if it's a living organism or an inanimate object cannot get below the ambient temperature regardless of the wind chill. Wind speed affects the rate at which heat is lost, but will not make the object colder than the ambient temperature.
For example: if an automobile is parked outside and the ambient temperature is a constant minus 20F, the automobile will never get colder than minus 20F regardless of the wind speed.
This discussion reminds me of the worst winter weather I ever experienced here in New Mexico. In the early 60's, we had a week of -65F at night with it only warming up to around -30F in the daytime. These temps were recorded at our weather station at the millsite. Official temps at the airport in Grants were in the -55F range.
Mark Twain supposedly said "One of the coldest Winters I ever spent was a summer in San Francisco" I'll bet he didn't worry too much about his coolant.