If you read the Label of ingredients in coolants, they are just a solution with a mixture of ethylene glycol and other corrosion prevention chemical.
Mixing of coolant will shorten the life spent of the coolants, it doesn't destroy your engine.
I won't write a chemistry essay to explain, but there are plenty on the web if you search, like why certain company formulate their coolant with specific chemicals.
You have about 2.5 gallon of coolants in your vehicle, adding few ounce of universal coolant will not change much.
2011 and older Chrysler vehicle all uses HOAT coolants, 2012+ uses OAT. There are a lot of similarity between OAT and HOAT, the differences is merely a presence/absence of few chemicals.
Last edited by steak59; 11-15-2012 at 01:17 AM.