I had been told that the different color coolants were developed for use in cooling systems that were made out of different materials. I don't remember which colors or formulations were for use with which materials. I have not given this issue any real thought for a long time. I also never researched the color vs. material compatibility issue to conform it's truth, so at this point, that can be considered hearsay, but the possibility may be worth considering.
it matters little what material the containment system is made out of to either type. and it is the truth that the two type so antifreeze are NOT compatible with one another, although they WONT gel up if mixed, like rumor has it, but mixing them will degrade the antifreeze properties of the mix, and you also lose the benefit of any additives, due to dilution.
EXCEPTION... there is a formulation that IS compatible with any color, and this may become the norm as time goes by.
the green conventional antifreeze lasts indefinitely, but should have a water pump lubricant added to it, and for maximum protection in any engine and especially diesels, an SCA should be used, and required by some engine manufactures, hence the use of the ELC, which
already has all these additives in it.
but the additives, especially the SCA degrades over time, and this is the main reason the coolant needs to be changed out.... with the green coolant, a bit more SCA only has to be added as required.
SCA (
Supplimental
Coolant
Additive), as generic as this name sounds, is a specific formulation that increases the protection of the cooling system other than just the antifreeze properties of ethylene or propylene glycol.... when additives are added to the glycols, the name changes from
antifreeze to
Coolant.... one can still buy antifreeze, but coolant has become the norm because of its increased benefits.
the there are only 2 reason that some would prefer the conventional green stuff over the ELC.
reason 1 being that its the good old fashioned stuff that has never failed them, so why change.
reason 2 being that, as the green ethylene glycol lasts forever, its cheaper to add SCA's to it every few years.
when one has a fleet of equipment and some of this equipment can hold as much as 30 gallons or more of coolant, it doesnt take long to get real expensive changing the entire system....
the ELC is excellent coolant in every respect, but it
does need to be changed periodically to maintain maximum engine protection...
with all this being said, aluminum blocks and/or heads, as well as diesel engines benefit from having SCA's in the coolant, and so to
insure the engine is getting its proper dose from owners who are a bit lax on maintenance, a lot of manufactures highly recommend the use of the ELC... but the conventional green will work just as well if maintained as it should be...