Engine Ice / Propylene Glycol vs regular Ethylene Glycol based coolant

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On my dirt bike I've been running Engine Ice, but never really thought about why. I do slow speed, technical riding that involves lots of clutch work and little airflow so keeping my bike as cool as possible is the priority, with boilover protection a close second priority.

Recently I learned there were two types of antifreeze - Ethylene glycol, which is used in the vast majority of coolants (green, dexcool, G-05, etc, etc) and propylene glycol, which is used by Engine Ice, and also Peak Sierra coolant.

On the Engine Ice bottle, they make several claims, saying it will have better operating temps than their competitors, which was enough to convince me to run it. Looking at the fine print, they say it outperforms their competitors, and lists Evans and Maxima. Since Evans is waterless I would assume it performs the worst, but I think the Maxima coolant is a regular EG coolant?

However, doing a bit of research, it seems like PG coolants run hotter than EG coolant, and the main advantage they offer is being non-toxic, and are not slippery (great for track). I don't ride on paved tracks, and don't really need a non-toxic coolant.

So how, exactly, does a PG coolant such as Engine Ice, outperform a regular EG coolant? If Engine Ice does in fact outperform EG coolants, why not run Peak Sierra which is also a PG coolant? Or am I wasting my money on a snake oil product and should I just run a normal EG coolant?
 
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Well, IDK the exact answer to your question but others will certainly chime in.
However, I always though that propylene glycol's advantage is that if spilled, it is less harmful to the eco system and also less/not harmful to animals that may drink it due to its sweet taste.
 
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Propylene Glycol is used as "Non Toxic" antifreeze in motor homes, toilets, etc. I tried to use the straight stuff in our cloud point tester at work for something safer than METHANOL, but the PG froze solid. It was full strength, but prob at -20˚ F.
 
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Propylene Glycol is used as "Non Toxic" antifreeze in motor homes, toilets, etc. I tried to use the straight stuff in our cloud point tester at work for something safer than METHANOL, but the PG froze solid. It was full strength, but prob at -20˚ F.
That's very odd, the freezing point of propylene glycol is below -70F. Even then it's like other glycols and makes more of a slushy solid. It's often used as an aircraft deicer due to the low melting point.
 
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That's very odd, the freezing point of propylene glycol is below -70F. Even then it's like other glycols and makes more of a slushy solid. It's often used as an aircraft deicer due to the low melting point.
I think you meant freezing point. Anyway, I bought the stuff from a local WalMart at the time, and I assumed it was full strength, but you are probably correct. The stuff I got must have been pre-mixed for motor home/camper use.
As a deicer, it might be melting point, but that's an unusual concept for me.
 
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Well freezing point and melting point are the same. In chemistry it’s often stated as melting point since that is easier to detect and define.

From what I find online -20F is about a 23% mixture.
 

jamesm113

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Freezing/melting point is not really a concern for me. The coldest nights my bike will ever see are probably mid-20s.

Most concerned with keeping my motor cool, and not boiling over.
 
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If your bike wouldn't see temps below -10°F I'd say increase water to 60:40 (destilled water/coolant concentrate). Water still has a superior thermal capacity compared to glycol. However at -25°F you'll unfortunately need at least 45 % antifreeze (concentrate). I don't see much else you could do except adding another radiator. A different coolant will likely do nothing.
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jamesm113

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Yeah, my bike won't see anything much below 25F.

I do need boil over protection, so I am worried about less than 50/50 AF/water mix. I have boiled over a lot with 50/50 EG/water, but I will say it seems to boil over a little less often with Engine Ice.
 

jamesm113

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The main question in my mind is why does engine ice say their coolant will be cooler? Is it just hogwash?
 
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The main question in my mind is why does engine ice say their coolant will be cooler? Is it just hogwash?
Without exact details it would be impossible to know. If there is a thermostat in the system and it is not out of control then that is what determines the coolant temperature not the coolant itself. I looked up the thermal heat capacity of the two substances and ethylene glycol is better so I don’t know. But that is dependent on concentration so one has to be very careful when reading claims such as this. A propylene glycol mixture at a lower concentration than a comparable ethylene glycol mixture might have better heat capacity.

I would use either one at the lowest concentration dictated by what it says in the manufacture literature and your expected operating temperatures.
 

jamesm113

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No thermostat in my dirt bike.

Engine Ice only sells a premix solution and they do not list the percent, but I think you might be onto something. If they are running a lower concentration of PG but have superior boilover/freeze protection vs EG, that would explain it.

They freezing point is -7F and boiling point is 254F. Looking at the freezing & boiling points of propylene glycol solutions, a 40% would have a freeze temp of -8F, but the boiling point would be 219F. Looking at the freezing & boiling points of ethylene glycol solutions, a 40% mix would have a freeze temp of -10F, and a boiling point of 225F - so an even wider range than propylene glycol.
 
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Biggest differences between an EG coolant vs PG coolant:

EG is toxic, PG is non-toxic
EG is more tolerant to extreme cold weather conditions vs PG
 
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