Anyone else running a lean coolant mix?

[JFP in PA]

Originally Posted by LAP1DOUG

I had always heard that ethylene glycol has a poor specific heat compared to water. Recently, I found this source confirming the reduced heat capacity of glycol solutions:

http://http://www.engineeringtoolbox.com/ethylene-glycol-d_146.html

So, when I flushed my system out recently after changing to a low temp. thermostat, I mixed up my brew with only 25% Porsche OEM glycol + 12 oz. Red Line Water Wetter + Water.

My test on this mixture indicate a freeze point of about 7F, which should be more than adequate for garage storage in Georgia, and a 14 psig pressure boil point of 258 F, which is only sacrificing about 4 F from the 50% solution pressure boiling point.

I searched on here, but did not find where anyone else was doing this. As I recall, most racing rules require 100% water for ease of track clean-up, but where there are no sanctioning rules to meet, I believe a lean mix is the way to go if your cold weather and storage conditions will allow it.

What you have done is increase the freezing point of the mixture, reduce the level of corrosion protection, shorten the life of the coolant mix, and throw in a useless additive that may further shorten the life of the coolant. I’d also bet you did not use distilled water either, which further exacerbates the shortening of the coolant mix life.

I’m not really sure how any of this is a positive……………

[BudmanV24]

Originally Posted by JFP in PA

What you have done is increase the freezing point of the mixture, reduce the level of corrosion protection, shorten the life of the coolant mix, and throw in a useless additive that may further shorten the life of the coolant. I’d also bet you did not use distilled water either, which further exacerbates the shortening of the coolant mix life.

I’m not really sure how any of this is a positive……………

Sounds like someone is mad that it's too cold in their area to run a mostly distilled water mix, lol. I ran this sort of mix for nearly a decade in the dirt bikes I raced with no problems and excellent results. I also run a very similar mixture in my boxster. The Water Wetter adds corrosion protection and reduces the surface tension of the water. If I'm not mistaken it's actually not too far off from dishwasher soap. If you're not seeing freezing temps, or pushing the car close to the point of boiling regularly, this is always a good mod to increase your systems cooling capacity. We all know that glycol doesn't transfer heat very well compared to water. This is also more environmentally friendly as you're using less of the toxic stuff.

[JFP in PA]

Originally Posted by BudmanV24

The Water Wetter adds corrosion protection and reduces the surface tension of the water. If I'm not mistaken it's actually not too far off from dishwasher soap.

"Water Wetter" is a cheap mix of surfactants that has been shown to often both lower the corrosion inhabitation of the OEM coolant, and then die off fairly quickly itself, leaving you with little, if any, corrosion protection. It was originally marketed in competition environments to lower the surface tension of pure water, which is fairly high as the molecule if extremely polar. Then the manufacture started marketing it as an additive for street cars (a much larger potential market), where unfortunately the coolant mix already has a fully chemically compatible and long lived surface tension modifier additive package of its own that obviously does not adversely react with the coolant package. Add in the fact that most people running pure water are doing so for other reasons (e.g.: race tracks hate anti freeze spills) and also tend to drain and refill they systems more frequently; and its utility on the street becomes even less obvious. A race car often has a cooling system fluid change several times a season, if not after every event.

Moving away from 50/50 coolant mixes to gain a heat transfer advantage is also somewhat of a fools errand because the real world actual differences are extremely small. You would gain a substantially greater degree of heat transfer capacity by going to a 160 degree thermostat and adding a third radiator of the car does not already have one.

The primary results are that the “lean” coolant mix needs to be changed more frequently, it will degrade the capability of the limited amount of coolant used, and could end up reacting with it in a way you did not expect; hardly an economic benefit in a car that is a pain to change the coolant in unless you have the vacuum charging system, which not everyone does. You might also be surprised how quickly the inside of one of these cooling systems gets nasty running a “lean” mix or only water and one of these "snake oil" surfactant mixes…………