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Topic: Antifreeze ratios (Read 650 times) previous topic - next topic

Antifreeze ratios

Some interesting reading about ratios of ethylene glycol antifreeze freeze to water.  This was a surprise to me and thought  others may find it interesting.  Thought it might be some help to those having overheating problems. 

Jason
Jason
1999 U320 36'

Re: Antifreeze ratios

Reply #2 –
Yup, 50/50 is optimum-- has been forever.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Antifreeze ratios

Reply #3 –
Brett please set me straight.  When I look at the specific heat capacity for a 25% mixture it is about .95 and for a 50% mixture it is abort .85 so we are loosing about 10% of the cooling ability by using a 50% mixture.  So if I was having overheating problems wouldn't a 25% mixture be better even though the boiling point will drop a few degrees.

The big problem with a 25%  mixture is the freeze point is only about 5 degrees so additional antifreeze would be required for winter.  So a 50/50 does not require winter adjustments making it easier.

Thanks
Jason





Jason
1999 U320 36'

Re: Antifreeze ratios

Reply #4 –
Actually, the percent is not the most important factor for a diesel, as preservation of the cylinder walls on any linered engine dictates a certain concentration of coolant/SCA or ELC/water.

Do you have an engine with replaceable cylinder liners?

But, in general, if a 10% loss of cooling capacity causes overheating, look for the root cause.  All chassis are overbuilt by that amount.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020
 

Re: Antifreeze ratios

Reply #5 –
Thank you for taking the time to explain.  I have the Cummins M11 ISM which does have replaceable liners. I was not working liner preservation into the equation.  I am not having any overheating problems but thought the information may be helpful to others.

Thanks again
Jason
Jason
1999 U320 36'