What Type Of Anti-Freeze Do I Use?

rpell1@msn.com · Oct 26, 2012

Hi,
I like to use Prestone and I always buy the full strength, extended life, un-mixed version. I prefer to mix the 50/50 myself. (I'm a suspicious control freak).

My experience has always been that the only thing that depletes in anti-freeze is the water pump lubricant. The alcohol always seems to retain it's ability to remain liquid. I change it about every 4 years.

NYSail · Oct 26, 2012

Well if you are referring to winterizing antifreeze get the pink stuff from west marine.

thinwater · Oct 26, 2012

rpell46 said:
Hi,
I like to use Prestone and I always buy the full strength, extended life, un-mixed version. I prefer to mix the 50/50 myself. (I'm a suspicious control freak).

My experience has always been that the only thing that depletes in anti-freeze is the water pump lubricant. The alcohol always seems to retain it's ability to remain liquid. I change it about every 4 years.

a. The "water pump lubricant" does not deplete. I'm in engine coolant manufacturing business, and that component lasts at least 10 years (dicarboxylic organic acid). In recreational marine service the only probable failure is contamination with seawater.

b. It is a glycol not an alchohol. Someone is going to quible that it is a double alchohol, but that is a superficial connection. The most likely breakdown products are glycolic and formic acid, which can become a problem in 5-8 years, depending on hours (generally about 8-10000 hours in truck service or bus service, based upon extensive fleet testing).

c. If you blend, use DI water, as required by ASTM and OEM specification. Bad water (containing sulfate, chloride or hardness) is one reason pre-dilute is common.

d. PG (winterization antifreeze) is NEVER used on engines isolated by heat exchangers. The corrosion inhibitor system is nearly absent and all wrong anyway. A diesel truck antifreeze, such as Final Charge or Prestone Heavy Duty, is a good choise. Though you can buy PG engine coolant (Sierra), there is a reason auto OEMs don't use it; it doesn't work as well (slightly inferior heat transfer agent). There is no environmental benifit, and you should recycle the spent coolant anyway.

Read the manual. The advise there will be sound.

Steve Dion · Oct 26, 2012

I would advise you to go with the mfg recommendations. If you are switching from the regular stuff to the pink/orange you had better be sure that your entire system is clear of the old stuff. We have had some posts where the two products were mixed and it can/will make a big mess.

Scott B · Oct 27, 2012

Are you talking the fresh water closed system or the seawater system.

Chris Patterson · Oct 27, 2012

Thinwater, you sound like a man who knows. What's all the stink about "Dexcool", or it's ilk? I thought this stuff was supposed to be the next hot thing in coolants, but the "advice" has been otherwise.

NYSail · Oct 27, 2012

Maybe I got his post wrong.... I did not read him to be changing his engine cooling anti-freeze. Sounded like he was looking for winterizing anti-freeze. The stuff we all buy from WM (or where ever) from the fall store displays and run through the heat exchanger and out the exhaust?

catsailor · Oct 27, 2012

Chris Patterson said:
Thinwater, you sound like a man who knows. What's all the stink about "Dexcool", or it's ilk? I thought this stuff was supposed to be the next hot thing in coolants, but the "advice" has been otherwise.

Dexcool is formulated for cars, not diesels, so I would favor one of the the heavy duty types (Final Charge, Prestone Heavy Duty, Cumins ES Complete and many others) as the "heavy duty" is actually the industry terminology for diesel. In simple terms, diesels clatter more that gasoline engines and that clatter induces a type of crevice corrosion automotive coolants cannot protect against so well. I would look for something that met TMC RP-329 requirements (truck maintenance council).

It is also my understanding that Dexcool has undergone a slight reformulation to address early compatibility problems. Dexcool was always a good product if kept uncontaminated, but in practice that twas sometimes difficult. The formulation is also tough on certain seal materials, most notably neoprene (the additives, not the glycol). It did not deal well with dirty systems and certain antifreeze types; it could gel and also leave odd patters of unprotected metal. Generally not a good choice for retrofit.

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I work for a coolant manufacture, though none of the above products are mine; we do not sell anything into the retail market.