BMW switched to HT-12 in 2019 I believe, which is 2-EHA free.
The US Army's Search for a Universal Extended Life Coolant Specification
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A little better explanation on why the saltwater test may be important:
www.army.mil
Army water purification systems can leave units running dry
Years of reliance on commercial water sources and optimistic water distribution planning may have set up brigade combat teams for critical failures in decisive action.
www.army.mil
Interesting Op-Ed there, and it fits nicely into the theme of Army self-criticism/improvement.
It's certainly true that military engines are more likely to be filled with poor quality water, but I don't think that was the primary motivation for the focus on this particular test.
The reports authors stated that:
"The results of ASTM D4340-19 with the blends are important because this study was designed using existing coolant compatibility tests performed by OEMs, which can be found in their coolant specifications."
From what I can tell ASTM D4340 was introduced pre-1990, and I found a reference from 1993 about using it to test compatibility of a candidate 2-EHA formulation with conventional coolants.
Engine Coolant Testing, Third Volume
Annotation Emerging from a November 1991 symposium in Scottsdale, Arizona, 19 papers report on advances in developing, testing, and applying engine cooling fluids for automobiles and heavy duty engines. Among the topics are carboxylic acids as corrosion inhibitors in engine coolant...
books.google.com
I was not able to see the reference for some reason.Interesting Op-Ed there, and it fits nicely into the theme of Army self-criticism/improvement.
It's certainly true that military engines are more likely to be filled with poor quality water, but I don't think that was the primary motivation for the focus on this particular test.
The reports authors stated that:
"The results of ASTM D4340-19 with the blends are important because this study was designed using existing coolant compatibility tests performed by OEMs, which can be found in their coolant specifications."
From what I can tell ASTM D4340 was introduced pre-1990, and I found a reference from 1993 about using it to test compatibility of a candidate 2-EHA formulation with conventional coolants.
Engine Coolant Testing, Third Volume
Annotation Emerging from a November 1991 symposium in Scottsdale, Arizona, 19 papers report on advances in developing, testing, and applying engine cooling fluids for automobiles and heavy duty engines. Among the topics are carboxylic acids as corrosion inhibitors in engine coolant...books.google.com
My post was in reference to high salt concentration in the water only and why poor water quality is less of a concern in regard to Army engines in comparison to personnel. Just a thought, since @JHZR2 brought up the question regarding high salinity.
During my time, BDAR fixes used whatever was available, to mix with whatever was available. Creek water, grey water, etc., along with whatever supply had in stock if it was even available. The only concern was to get out of the area and concentrate on personnel first.
I suspect the idea may be that in a hostile environment, a BDAR fix is implemented (punctured radiator), but not all coolant is out of the block/system. Whatever water is available is added so the vehicle can depart the area ASAP. In that circumstance, gelled coolant two minutes later would be a big problem.
For example, a radiator puncture (regardless of cause) is repaired by punching out the fins in the area and bending the tubes shut. Less than a minute. Refill with whatever and get back to the mission (retrograde or otherwise). If saltwater would gell the AF in the system, that would be a very big fail.
"Mixing effects were examined by combining coolant 2 with two conventional North American coolants. ASTM D 4340 was used to evaluate performance. Representative samples of the North American coolants were obtained in the aftermarket. The North American coolants were phosphate buffered and had both high and low silicate levels. Theses coolants passed ASTM D 4340 when tested alone. In all cases there was a range of mixtures with corrosion rates greater than the specification for ASTM D 4340 in ASTM D 3306 (1.0 mg/cm2/wk)."
There's more but I don't feel like typing it all out, it's an interesting report about the early investigation of OAT coolant including 2-EHA, even if there are some pages removed.
Yes, it certainly is more of a concern, which is probably part of why they decided to run the D4340 test again on non-mixed samples of the two downselected candidates:
"ASTM D4340-19 is a screening test used to evaluate a coolant’s ability to prevent corrosion of aluminum. This test method was run under WD 002 on all the ELC blends, but since it had not been run on the pure candidates, which is a requirement of ASTM D3306-20, it was decided to run ASTM D4340-19 on each OAT candidate individually as well. As expected, just like when the two candidates were blended together, each one alone produced passing heat-transfer corrosion
rates (the highest result being 0.3 mg/cm 2 /week) and no precipitates were formed."
There's a lot of good info hidden away in military training publications, I've ran across some BDAR ones before and they were quite enlightening.
Any updates on this topic by chance?
The comments on 2-EHA is where the “study” comes off the rails. The 2-EHA was never proposed for wet sleeve diesels, but they didn’t clarify that, just more “bad,bad,bad”comments on 2-EHA.
The latest, greatest 10 year, all makes coolant from Prestone contains 2-EHA. I’ve run Dexcool for 16 years without problems. The rest looks good. Thanks for the posting.
The latest, greatest 10 year, all makes coolant from Prestone contains 2-EHA. I’ve run Dexcool for 16 years without problems. The rest looks good. Thanks for the posting.
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