Ethylene vs. Propylene Glycol

[SZR48207]

I'm hoping someone here can tell me if my memory is correct.

Have most coolants available at the big retailers always been formulated with EG? I'm talking brands such as SuperTech, Prestone, etc..

I swear that it seems like 4-5 years ago, everything was made using PG (post dex-cool lawsuit era). Because of this, it seems like everyone had to go out of their way to buy Zerex G-05 since it was one of the only off the shelf EG formulations that you could get (all the other brands were PG). I remember lots of stories about people going from EG to PG and then their vehicle cooling systems clogging up because air would get into the system, etc..

 

[Rolf]

Originally Posted By: Reddy45
I'm hoping someone here can tell me if my memory is correct.

Have most coolants available at the big retailers always been formulated with EG? I'm talking brands such as SuperTech, Prestone, etc..

I swear that it seems like 4-5 years ago, everything was made using PG (post dex-cool lawsuit era). ....


Nope.

Propylene Glycol has a problem: it does not conduct heat as well as Ethylene Glycol.

In order of efficiency in conduction, it's water first, ethylene glycol second, and propylene glycol last.

This means that in any sort of condition on the edge: towing a trailer in Death Valley, climbing Pike's Peak - propylene glycol will make your engine run hotter.

It's like putting a smaller radiator in your car.

The benefit is that propylene glycol is less toxic than ethylene glycol. Less toxic, not non-toxic.

Consume enough and you'll have a problem.

 

[Vilan]

I think you're confusing PG with Dexcool, Reddy. At least from the stories I read here, the problem is usually people who use Dexcool and end up with a mess, and then go looking for traditional green coolant. But traditional green and Dexcool are both made using EG; it's the different additives that cause different reactions. PG coolants have usually (always?) been fairly obscure and need to be specifically searched out.

 

[kingrob]

Almost every type of coolant since 1926 has been made of ethylene glycol, dex-cool and "long-life" green included. The difference between the different EG formulas comes down to silicates and phosphates. Now people half-arsedly throw around "Ethylene Glycol" as if it relates only to old-school traditional green, a misnomer for sure.

I first started seeing PG in the eighties. It is almost always used in a Low-Tox Formula. It was also the first non-green coolant I remember seeing, coming in a orangy-pink formula that looks like what Prestone OTC Dex-cool and Toyota Red would look like if mixed. I remember seeing the commercials for Prestone's formula showing a dog drinking some PG and the owner shooing him away, then the ominous voice over "If this was traditional anti-freeze, you would have just lost your best friend..."

FWIW my friend left a pan of his drained Low-Tox under his car in his backyard thinking that the dog wouldn't be attracted to it like regular anti-freeze, with tragic results. It only took about a pint of 50/50 mix to kill a healthy 100 pound German Shepard. Not much safer than EG if you ask me.

 

[Asterix]

Wikipedia has a quick overview of this, which jives with my understanding: http://en.wikipedia.org/wiki/Antifreeze

PG is used as a food additive. PG-based antifreeze surely has other stuff in it that is toxic.

I suspect a typical water line antifreeze for RVs and such is based on PG. It's not meant to transfer heat like engine coolant is.

Propylene glycol breaks down in your body to ethanol and its byproducts.
Ethylene glycol breaks down to methanol and its byproducts, which are toxic.

Asterix

 

[vxcalais]

PG is even in facial creams cosmetics etc etc. What are your experiences with Amsoils Coolants made from PG ? I was about to post a thread on it when i saw this one(Instead of making another one). Im interested in using it cause if also claims it has leak sealing ability. The Amsoil PG shows similar hot and cold performance to mainstream EG products.

 

[DmanWho]

There are three (3) basic types of coolant available in the market today. Ethylene Glycol Silicate Based, Ethylene Glycol Phosphate Based, and Organic Acid Based. The color of the coolant has nothing to do with the actual base coolant and is only the dye added by the coolant manufacturer.
The only way to properly identify the type of base coolant is to READ THE LABEL.

-For our SX4, the manual states:
To avoid damaging your cooling system: Always use a high quality ethylene glycol base phosphate type coolant diluted with distilled water at the correct mixture concentration.

 

[doitmyself]

DmanWho, you forgot "conventional" coolant that has BOTH silicates and phosphates. That would make 4 basic ethylene glycol types.

 

[DmanWho]

Thanks for pointing that out...

My post was a copy from a Daewoo TSB. (TSB No. TS 02 01074)
Here's what else it said...

For our new Verona and Forenza vehicles, the proper coolant to use is the Ethylene Glycol Silicate Based coolant. The proper mix is 50/50 coolant to water* and in no case higher then 70/30.
Concentrations greater then 70/30 coolant to water will cause overheating conditions.

For all other Suzuki automotive products, the proper coolant is the Ethylene Glycol Phosphate Based coolant. Again, at a 50/50 coolant to water* mix, not to exceed 70/30.

*It is strongly recommended that either distilled water is used to mix with concentrated coolant or a "pre-mixed" coolant is used. This is especially important in areas where the tap water has a lot of dissolved minerals (Hard Water). The presence of an abundance of dissolved minerals may cause the
Silicates or Phosphates to drop out of suspension and cause cooling system malfunction. (i.e. rapid seal wear, block corrosion, passage way and/or radiator blockage.)

WARNING:
DO NOT MIX DIFFERENT TYPES OF BASE COOLANTS. MIXING DIFFERENT BASE COOLANTS MAY RESULT IN ACCELERATED SEAL WEAR AND/OR THE POSSIBILITY OF SEVERE OVERHEATING AND EXTENSIVE ENGINE/AUTOMATIC TRANSMISSION DAMAGE.