AC guys, I have a question.

Jan 2, 2004
I was under the understanding POE and PAG oils were miscible but I read a few posts on other forums that it’s not advised. I’m debating picking up a UView Spotgun Jr. or Eco-Twist kit to add a little oil and UV dye to a friend’s Subaru. The one I’m looking at has POE oil for hybrid/electric compressors, like the one used on a Prius. Those compressors require a ester oil with high dielectric strength - else any electrical “leakage” is enough to throw the CEL, log chassis codes for high-voltage leakage and disable the HVAC system. I would like to keep one injector around.

So, can I mix POE oil with PAG oil or no?
I always heard ester oil is compatible with both mineral oil and PAG but PAG and mineral oil are not mixable. Mineral oil was used in the older r-12 AC