Diesel Power, let me address some of your concerns. Let me state that I am a specialist with engine coolants, coolant chemistry and associated maintenance. Have been for 19+ years. I have seen all those changes you speak of over the years. Yes, the coolant industry (blenders and engine companies) have managed to change something relatively simple into what amounts to mostly marketing and sales rather than leading edge technology.
Old World Final Charge does have a special test kit for that coolant. While I have seen the kit, I have not had the opportunity to see what it tests for. A vendor company that makes our conventional test strips was working on test strips that could detect organic acid inhibitors. What is not known now is if those strips are chemistry specific or just measure OAT in general.
Per your comment about Cummins and the bottle of silicate fluid, Cummins did not furnish that. The original issue that brought that about was Texaco OAT extended life antifreeze formulated with ethyl hexanoic acid (EH). That acid turned out to be the cause of a major gasket failure issue for Cummins and to some degree on Caterpillar. That OAT acid attacked silicon rubber and Buna Nitrile O-rings. The silicon backbone molecular chain was destroyed causing the elastomer to shrink allowing coolant leaks. Normally, silicon rubber gaskets remain pliable for years and are "gap filling". It was determined that if a silicate film could be applied to those gaskets before the Texaco ELC coolant was installed into the system, the silicon rubber had a much longer service life. Originally, Texaco, then Shell and later ChevronTexaco supply the silicate fluid. For engines that do not use silicon rubber or Buna N elastomers the silicate fluid is not needed. An interesting side note is that while International Truck was installing the silicate fluid into Class 8 road tractors they built with Cummins ISX engines filled with International's standard factory fill (Shell OAT), it did not occur to them that they needed to do the same for some DT466 and DT530 engines filled with the same coolant. They learned they needed to have the silicate fluid as well. There was no problem of long gasket life in Cummins and International when filled with conventional chemistry coolant. Then along comes Texaco to upset the status quo. Sometimes "new and improved" is not such a good thing.
I'll ignore that comment about blue coolant
But I will say that drivers of trucks often have difficulty checking the oil, especially fleet drivers. Owner operators are much more in tune with their trucks. If they do not know, they can suffer great monetary loss from ignorance. Fleet drivers just do not give a flip as somebody else has to fix what they mess up.
As for stocking two coolants, one conventional chemistry like the Fleetguard product you mention (ES Compleat? or ??) and the Caterpillar ELC. The issues with Cummins engines and silicon elastomers are still with us. If someone have a coolant that they are at least sure is NOT one of those OAT formulas I mentioned earlier, then topping off or refilling with the Fleetguard is an acceptable practice even if the coolant is not the same color. The colors of coolant per the coolant manufacturers is largely a matter of brand recognition. The TMC has enacted a coolant color standard as a way of identifying the coolant chemistry used. Many manufacturers have not adopted that standard. Only Shell has to my knowledge. Mixing of conventional and OAT chemistry is not really a problem, not like the problem that one company or another will state. When coolant companies say things like that, they are trying to scare customers and promote more sales.
What is the difference between OAT and Conventional?
OAT
ethylene glycol base
organic acid corrosion inhibitor (3 - 10%)
nitrite
molybdate
defoamer & dye
no silicate
no buffers (antacid additive)
little reserve alkalinity
Conventional
ethylene glycol base
minimal use of organic inhibitors (<1%)
nitrite (cavitation protection)
molybdate (cavitation and aluminum protection) (not used in
Fleetcharge and some others)
defoamer & dye
low silicate levels per ASTM D4985
buffers, borate and/or phosphate
generous reserve alkalinity
There is more to this story as to what each of these chemical additives do but suffice it to say that mixing them has NO dire consequences. The worst effect you get is that when two dyes are mixed the resulting color sometimes is not so good to look at. Like mixing green kool aid and red kool aid resulting in a brown to black liquid. Just close your eyes and take a drink.....it still tastes like kool aid. Engine coolants are the same. The no mix story is just baloney made up by marketing and sales people.
One last note, you are thankful that you are in the oil business. Me, I am thankful I am not as it is easier to differentiate coolants and SCA than to show the differences in lubricating oils. At least to me that is how I view it. Glad you are there for the lube oil end of the business.
