Skyactiv, thank you very much for the info and useful chart! I hadn't found that, but I'm sure it will come in handy again.
Simple_Gifts, kinda testy for somebody with a bunch of posts on a forum where I'm sure I've read more than a few posts to the effect of, "My wife/girlfriend put a quart of the wrong brand of (the appropriate motor oil) in my car!! I'm having it towed home to change it. How many seafoam flushes do I need to do before I can drive it again?" It ain't like I called your cell to ask, or suckered you in with a misleading title. j/k
Seriously, thanks for being a resource. This generator thing is a volunteer effort, and believe it or not, I've wasted hours on this between my real work, calling the dealer - who didn't know what I needed, calling Cummins, and getting no answer, and searching the web. I spent plenty of time on Cummins blue coolant, but never thought to search Onan coolant.
I resisted asking, but eventually I decided that somebody on BITOG probably had this info on the top of their head, and sure enough! Thanks again Skyactiv!
And the linked chart is great IMO. It groups the families of coolant in an easy to reference format, without the need for hours of geeking out.