Charles,
It's nice to hear that you use Prestone antifreeze, but I didn't know it was orange. I guess that's the new formulation. You say your block and head is solid cast iron, you must drive a MB diesel. But how about the radiator? Is it aluminuim?
Scott,
You have again written a long and interesting treatise on why we should use MB antifreeze(Zerex). Me and my 5th grade class agree with a lot of the things you write about, but some of the things you write are hard to believe. For instance; about "things" droping out of non-MB antifreeze causing clumps to cling to the interior of the cooling surfaces and blocking cooling passageways, cause hot spots,etc. I have rebuilt over 50 MB engines over the past 34 years and I have never seen anything like the things you mention. Those engines that I have rebuilt have had all the different brands of antifreeze, and I was always amazed at how clean the interior of the engines were.Have you ever rebuilt a Mercedes engine?
I know you have done a lot of reading on antifreeze, and I admire you for doing it. But me with my 5th grade education do not believe all I read. If I did I would be a multi-millionair, and I would be cured of all my aches and pains.
Scott, you keep mentioning the use of "a phosphate based anticorrosion agent" in antifreeze(like Prestone)that causes "things" to drop out and stop up the cooling system.I don't know which phosphorus compounds are used in antifreeze solutions, but phosphoric acid is a fairly weak organic acid, and I don't think it's harmfull to aluminium. It is good for removing rust(but citric acid is better, and contrary to someones prior statement, it will not harm your skin.) Phosphoric acid is used in the food industry to clean their processing equiptment.
These things about drop outs clogging the cooling system I have never seen, but then, I have not read all the literature. Just experence. Sometimes we need to get out and smell the grass. Not necessarly the green grass. How about Bluegrass? Kentucky Bluegrass.
Read your owners manual, and by all means read the labels on the "other" antifreeze brands. Choose wisely, and I know you will choose Zerex. So be it.
Bill Lewallen;Lexington,Ky.
Home of Valvoline Oil - Maker of Zerex