Author Topic: Antifreeze mixture for this cold spell  (Read 1519 times)

Offline p7387

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Antifreeze mixture for this cold spell
« on: January 13, 2018, 11:04:09 AM »
Hello
I suppose this pertains to any basic small block motor in our classic older vehicles.

I typically use a mixture of 50/50 prestone and leave it at that. What's the reality of damage due to freezing in this extreme cold for these classic vehicles typically not being used regularly in winter.

My vehicles are in upstate New York where on a few occasions the temp got down as low as -20 for a bit

Thanks

Offline zieg85

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Re: Antifreeze mixture for this cold spell
« Reply #1 on: January 13, 2018, 12:02:46 PM »
Most full strength antifreeze bottles have a scale on how to mix with water.  I usually go 60/40 for Chicagoland.  Even that it may get colder it never stays that way for long.  Go 70/30 to give you peace of mind.
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline Henry

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Re: Antifreeze mixture for this cold spell
« Reply #2 on: January 13, 2018, 01:33:53 PM »
Hi P8387:
If you are sure your antifreeze mixture is at least 50/50 you should be fine at -20F as my bottle of Prestone says it is good for -34F at 50/50. On older vehicles such as ours the concern at these low temps is the plastic and rubber parts becoming brittle and breaking under movement and vibration before they can warm up....like seals and wire insulation...also think about your windshield washer bottle's solvent rating...make sure you have a good antifreeze in it as well. Just dont drive your truck in this real cold stuff if you dont have to. If you have to, test your brakes before you leave your neighborhood: I drove out of my neighborhood on ice and when I hit my brakes for the first time the pedal went to the floor...it was fine in above freezing temps. The master cylinder seals failed under the +20F temps.
Regards,
Henry

Offline hatzie

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Re: Antifreeze mixture for this cold spell
« Reply #3 on: January 14, 2018, 11:03:30 AM »
I have to agree with Henry.  Old hoses, belts, plastics, etc are a bigger issue on an old vehicle at the mid -20°F temps.

-34°F is the start of ice crystal formation on a 50:50 mix.  You will not freeze up and damage an engine at -34°F using that mixture. 
You're only getting -25°F at the worst of this.  At -25°F Wind Chill numbers near the -40° range is a "Feels like" number.  It just means at higher wind speeds vehicles, pets, and humans don't take as long to get down to actual temp of -25°F so don't expose your skin to the blowing wind. 
I grew up in Central NY farming country between Binghamton and Syracuse and then Upstate in Hoosick Falls NY just outside Bennington Vt and North Adams Ma. 
I've only seen -35°F in Sherburne NY once...  Over Christmas 1981 or 1980.  It set a bunch of records.  Alba-Schenecta-Troy, Lake George, and Plattsburgh generally run higher temps in the winter than the higher elevations around Cooperstown, New Berlin, Sherburne, Hamilton, and Norwich.  We always ran 50:50 in everything.

Most of these trucks are not daily drivers anymore.  Since they primarily operate in summer weather heat is more worrisome.  50:50 transfers heat better than 60:40 or 70:30.
« Last Edit: January 14, 2018, 11:06:29 AM by hatzie »
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