In Sheridan, Wy at the International Truck Parts store I bought some Shell Rotella ELC. Nice pink color as expected.
A few days later at the International Truck Parts store in Spokane, Washington, I bought some more Shell Rotella.
Much to my surprise, when I opened the Rotella from the Spokane store, it was YELLOW! OMG, this looks like Prestone.
On closer inspection of the jug, I saw it was labeled "Shell Rotella Ultra ELC".
So off to Google I went.
From the Rotella ELC data sheet:
"Shell Rotella ELC contains a Unique Extended Life carboxylate Inhibitor System and Nitrite / molybdate as Secondary"
"...meets Cat EC-1..."
From the Rotella Ultra ELC data sheet:
"Shell Rotella ULTA ELC Contains OAT Corrosion Inhibitor Technology..."
"The product is free of nitrites, amines, phosphates (NAP), borates and silicates."
"...compatible with other engine antifreeze of similar type..."
"...meets Cat EC-1..."
When I called Shell a week or so ago, they told me Shell Rotella ELC could be mixed with any other coolant that meets Cat EC-1. So, I'm assuming I can mix the two. I would prefer not to, but I guess I will in a pinch.
I can't answer your question on different Rotella anti-freeze, but it demonstrates to a T that we are not in the old world of just Prestone green. There are so many different choices and different opinions, that nobody is sure of what will not work and what will. Often it is not even known what is in their cooling system. When changing coolant, a couple of extra gallons of the same stuff should be carried and hopefully when it runs out, the same stuff is still available.
I agree, we are in a new world as coolant is concerned. I will never mix. I would prefer to add water until I got the correct anti freeze. I have seen some horror stories when incorrectly mixed. I am not sure I understand the need for all the incompatible coolants.
It use to be so simple. Prestone or Zerex, easy to identify.
Jerry