Hah-This reminds me of something I wanted to post a while back, but forgot about.
Bobcats, as we know, come out new filled with the purple propylene glycol, “non-toxic, environmentally-friendly” coolant. The big thing was that ethylene glycol, or green stuff is poisonous, and also sweet-tasting, which is a bad mix around children and animals. Okay.....
I went on Kubota's website and they do NOT recommend using anything other than ethylene glycol for their engine installations, for various given reasons, and that's available in the FAQ section on that site. And I found that interesting.
So from what I got from the website, is that the old school coolant (green, ethylene glycol) mixed properly, absorbs and gives heat more readily than the purple tree-hugger brand, and that designers have to take this into account when designing cooling systems.
I have seen a few Bobcats over the years, both loaders and mini-excavators, that seemed to be lemony over-heaters. Always the purple coolant, through the dealer.
My old pop has a nice T300, I'm gonna drain that shtuff out and put green in it, and I am going to recommend to all my customers that they let me change them over to green and peel that decal. Most customer-maintained machines anyway have been mixed. The purple stuff, keeping it that way, is just not practical.
I heard another guy a while back state that instead of requiring manufacurers to use this expenisve, non-toxic coolant, they could have simply added an embittering agent for a few cents per hundred gallons of poisonous but sweet ethylene glycol.
And that's a rant for the day.......=).