Here we go again , OAT or IAT antifreeze

gpits68

gpits68

Senior Member
We are looking to put antifreeze in our A's for winter storage . We don't want to just drain them and leave them , but instead add antifreeze in case we want to run them sometime this winter . From what I have found , we want an IAT antifreeze and not an OAT antifreeze . I purchased the Prestone Lowtox because I could not find the highly recommended Sierra . After looking to see if the two were similar on the MSDS's ,I see that they both have Propylene Glycol with seems to put them in the OAT category which is not recommended in old cars . What to do , what to do.................
 
BudP said:
xerex original - It's available all over and online.
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Thanks for the reply BudP , We are hoping to use the antifreeze that is pet friendly (since A's do loose antifreeze and animals frequent our garage ) but we want Model A friendly as well .
 
Thankfully my car's previous owner kept antifreeze in it year round. As a new owner this past spring I drained the coolant and it was amazingly clean. My car with 50/50 this summer never over heated a single time.I use Prestone that I mix myself with distilled water.
 
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The coolant drains completely why not drain water and when you starting
this winter you could just add water and then drain hot water after more
pet friendly yes :-)
 
Just checked prices of Sierra on Amazon as I could not find it locally either.
At about $135.00 a gallon for the Sierra, I believe I will use the same low silicate anti-freeze that I use in my diesel truck and fix any leaks in the "A".

Ray
 
I keep antifreeze in my cars year round. It is a great rust inhibitor and water pump lubricant. I leave it in 2 years and then replace it. I know it costs more but I use the Prestone 50 / 50 premix for the convenience ! You just pour it right out of the jug !
Wayne
 
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gpits68 said:
Thanks for the reply BudP , We are hoping to use the antifreeze that is pet friendly (since A's do loose antifreeze and animals frequent our garage ) but we want Model A friendly as well .
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They do?:confused:

They shouldn't. If they leak, then something needs to be fixed.:)
 
Big hammer said:
The coolant drains completely why not drain water and when you starting
this winter you could just add water and then drain hot water after more
pet friendly yes :-)
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Thats what I do I use water pump lubricant in the months that we drive and it prevents rust . I've never had a problem . It doesn't get all that cold here and if we want to go for a ride we just add water and go. I keep most of mine inside year round anyway .
 
Propylene Glycol is of course pet friendly; it is inert, too. I have never heard that it is somehow 'bad' for 'old cars'

exactly what effect does it have that is bad?

If any antifreeze gets in your bearings it will harm them but I do not think that is what this thread is about.
 
1930 coupe said:
I use standard Prestone 50/50 year round for 45 years, and never had any trouble with it. I drain it out every 4 or 5 years if it needs it or not and put in some new. It always comes out as clean as the new antifreeze.
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I agree with this. But do look for the correct Prestone like mentioned above.
 
When I used antifreeze in the model A's I mixed one gallon of pure antifreeze with two gallons of water and that would prevent freezing at temperatures way colder than it ever gets here . When I used antifreeze I only used it in winter to prevent freezing . Antifreeze flows out the overflow tube in unpressurized cooling systems, leaks in places that water doesn't and causes model A's to run at higher temperatures. When I used it I constantly had to add more. Unpressurized systems really need to be constantly monitored to maintain proper levels .
 
Hey Ray,
Hmm, $135.+ PER GALLON :) !! Wow, think that I'll sell the couple gallon that I have stored...at that price. Think that I paid approx. $16. each.

Anyway, I notice that some say...it came out really clean after so many years. The efficacy of anti-freeze is lessened with time and according to PM schedules of new engine / car makers , should be changed on a schedule.
 
I bought a 2.5 pound cap assembly that bolts to the left front hood latch bolts and plugs into the radiator overflow. Then I cut a thin gasket, from a jar lid removing aid sold in grocery stores, and put it under my moto-meter. It works wonderfully, no spilled antifreeze and no loss of water. Moto-meter works just fine. I added a recovery tank on the outlet side of the radiator cap do-hicky and have since removed it. water never went there, even on hot days in the mountain climbs of the Sierras. Surely not right for everyone, but works for me.
 
WOW is right, I recall a few years ago when it was just slightly higher than Prestone etc. heck you can buy some drinking stuff cheaper than that.

135 gal, but you get free shipping, guess I'll just have to put cats beware on my Prestone fed model A's

Sierra Antifreeze-Coolant Propylene Glycol $135 Free Shipping
 
Benson said:
This is not aimed at anyone ... just a statement for those that may not know it!

Lately stores have two versions of antifreeze.

1. 100%- you mix it 50-50 as always. Freezes at -34 degrees.

2. The second one is cheaper called 50-50 premix ... If you do not notice that it is premixed and you mix it 50-50, it freezes at about 10 degrees above zero!

This is a stupid idea and there will be many engines ruined by this "marketing strategy"!
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I truly believe most members on Fordbarn are intelligent enough to know the difference. I personally find it a very convenient method of carrying extra antifreeze and not having to judge the amount to be mixed. Wayne
 
Sierra brand propylene glycol (PG) anti-freeze is also available at NAPA for around $16-$17/gallon.

Remember though that PG anti-freeze requires a special tester and the tester for polyethylene glycol (PEG) will not provide an accurate measure of PG anti-freeze.
 
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