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LAP1DOUG · 03-04-2012, 05:44 AM

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.

03-04-2012, 05:44 AM	#1
LAP1DOUG Registered User Join Date: Aug 2011 Location: USA Posts: 414	Anyone else running a lean coolant mix? 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. __________________ Kippis 986S 991S Van Diemen RF97 Last edited by LAP1DOUG; 03-04-2012 at 05:47 AM.