Freezing Point - Best Mixture

[AaronC]

Does anyone know what the Freezing point is for a 50/50 Methanol-water mix?

Also, what is the best mixture for performance? 50M/50W? Or would a 25M/75W be better?

[AaronC]

Well, I found some info on this and I thought I would share:

Methanol \ Water Mixtures

Methanol Conc.
Wt. % (Vol.%)---Freezing Point,F(C)---Flash Point, (TCC) F(C)
0(0)--------------- 32(0)--------------- No Flash
10(13)----------- 20(-7)-------------- 130(54)
20(24)----------- 0(-18)-------------- 110(43)
30(35)------------ -15(-26)------------ 95(35)
40(46)------------ -40(-40)------------ 85(29)
50(56)------------ -65(-54)------------ 75(24)
60(66)------------ -95(-71)------------ 70(21)
70(75)------------ -215(<-73)---------- 60(16)
80(83)------------ -225(<-73)---------- 55(13)
90(92)------------ -230(<-73)---------- 55(13)
100(100)---------- -145(<-73)---------- 55(13)



Isopropanol / Water Mixtures

IPA Conc. Vol. % (Wt.)--Freezing Point, F(C)----Flash Point, (TCC) F (C)
0(0)---------------------- 32(0)------------------ No Flash
10(8)--------------------- 25(-4)----------------- 105 (41)
20(17)--------------------- 20(-7)----------------- 85 (29)
30(26)--------------------- 5(-15)----------------- 75 (24)
40(34)--------------------- 0(-18)----------------- 70 (21)
50(44)--------------------- -5(-21)---------------- 65 (18)
60(54)--------------------- -10(-23)--------------- 65 (18)
70(65)-------------------- -20(-29)--------------- 65 (18)
80(76)-------------------- -35(-37)--------------- 65 (18)
90(88)-------------------- -70(-57)--------------- 65 (18)
100(100)------------------ -130(<-73)------------- 53 (12)

[Brad]

Good information. The mixture for best performance is based on a combination of air fuel ratio and temperature of air being cooled.
If the engine is running 12/1 a/f and has a manifold inlet temp of 200F water is best. If you have a a/f or 13.5/1 with 200F manifold temp them a mixture a methanol would be in order.
If you have a intake manifold temp of less than a 100F a higher consitration of methanol would be useful if you can adjust the fuel ratio.
There is not one ratio that is correct for every application. You will need to test to find you best balance.

[AKWRX]

The mixture freezing lists above appear to have been sourced from data using chemically pure water. Pure water with no ice nuclei to start the freezing process can be chilled to -40 before changing state to ice. In the atmosphere it is not uncommon to have "super cooled" unfrozen pure water at -15F, or colder in clouds. In the real world, alcohol/water mixtures contain many other contaminates that act as ice nuclei, so the practical freezing points are not nearly as cold as those listed. For example, windshield washer fluid with a 50/50 mix of methanol also has detergents and other particles that serve as ice nuclei. The actual freezing point would be closer to -20F, rather than the listed -65F. I have observed an 80/20 mix of methanol (in a not too clean can) cold soaking outside to have the water visibly start to slush up at only -70F. Also, note that there are typos on the methanol freeze points for the 70, 80, and 90 percent entries (100 degrees off).

[JohnA]

Very useful information Aaron, I was actually looking for it!

I'll use these tables on my website, if you don't mind :lol:

[Forum Admin]

Good comprehensive and informative site too.

[JohnA]

He he...thanks :D

[boostm3]

Heres the problem I found this winter. Here, we had frequent bouts with temperatures well below 20 degrees F. When it got down to near 10, I found that even a 45% methanol mixture, while remaining liquid in its reservoir, would ice up within the 4mm nylon lines. It never burst, since I believe most parts of the system remained liquid, but it wasnt thrilling to see the ice in the nylon lines Ill tell you! I just think that in these very small lines, it can be extremely hard to keep things liquid down below 15 or 20 degrees F. At least, with most of the system remaining liquid, overall there were no problems.

[Richard L]

This site has a very comprehensive account of all the screen washer mix and freezing point tables.

http://www.ashchem.com/adc/chemicals/faq_answer.asp?typeID=3&is_header=N

[masterp2]

Heres the problem I found this winter. Here, we had frequent bouts with temperatures well below 20 degrees F. When it got down to near 10, I found that even a 45% methanol mixture, while remaining liquid in its reservoir, would ice up within the 4mm nylon lines. It never burst, since I believe most parts of the system remained liquid, but it wasnt thrilling to see the ice in the nylon lines Ill tell you! I just think that in these very small lines, it can be extremely hard to keep things liquid down below 15 or 20 degrees F. At least, with most of the system remaining liquid, overall there were no problems.

I have just an educated feeling about this. A water/meth solution, loses the meth to evaporation 4x faster than water, so, with time, the solution is weakening, hense the greater likelihood of freezeup. Factor in frequent heatups inside the engine compartment, this is a reasonable explanation.

A small amount (line) will freeze sooner than a large amount as the temps swing. Ice cubes in the freezer are the same way.

[1 Quick Bunny]

Good comprehensive and informative site too.

Yeah, thats an AWSOME website John! Actualy it answered questions I was having about VW's and Fram filters!

[JohnA]

Yeah, thats an AWSOME website John! Actualy it answered questions I was having about VW's and Fram filters!
Thanks mate :D

Shame that I haven't got enough time to spend on it lately, it's ripe for a complete re-design (as the dodgy navigation suggests...)

[1 Quick Bunny]

I gotta thank you again! I actualy had a Fram fail on me and apparently it was instrumental in wiping my oil pump out. Caught it in time that it appaers no other damage was done to the engine. I just ordered a filter can opener and will further diagnose what occured. The pump looked like it had sucked up a fistfull of sand! Fortuantly it SEEMS that whatever went through the pump never hit the engine bearings, they looked good.

Thanks again, and my Pops also says thanks. He just bought filters for his van based on the article!

The rest of the info on your site is also very cool! A request thats not covered anywhere I can find, more information on oil breather systems. I can't find much of anything difinitive out there... EDIT: found your info, but MORE is always a good thing! Perhaps a theoretical discussion about cars not originaly equipped with a turbo.