While changing out the three decayed hoses in my cooling system I lost some antifreeze, actually it went into a dirty bucket, some had rolled down the side of the engine....I needed 4 gallons of new. The Cummins Store was closed, I usually buy Fleetguard that meets DD Spec, but Joe Baggadonuts Heavy Truck Repair was open. I acquired the anti freeze from him and asked him some questions, his answers puzzled me so that I did some research and now I am even more confused.

There are basically two types, ethylene and propylene, the later being far less toxic to animals and humans. Ethylene glycol provides the best heat transfer and is the product used in heavy duty engines, and it never wears out. What does "wear out" are the additives in coolant. Extended life antifreeze only means that the additives last longer. Additionally, it is best to buy pre-mixed (50-50) antifreeze because it is mixed with de-ionized water. I have always mixed it and used distilled but evidently that is not a good answer; tap water with chlorine and high amounts of TDS (total dissolved solids, calcium and the like) is really a no no. Many of the lower priced antifreeze products are made from recycled or used antifreeze. Thats what my reading showed.

Back to Joe Baggadonuts. He said that all ethylene antifreeze is the same whether you buy it from Detroit Diesel or Wal-Mart. The additives are much the same in all of them; evidently there are several government agencies monitoring this and set the specification because it is considered toxic. Further the coolant filter (sounds like it contains a bunch of rocks in it when new) continually refurbishes the additives (SCA's) to prevent scaling and jelling. The biggest danger he stated is the running of too high concentration of ethylene.

So my question is, was Joe full of sierra hotel india tango or was he right...I dunno!

John