Who really cars? I'm 49, been with Trane 18 years and I work on whatever they give me. By time anything changes I won't be doing this anymore. R134a and 410a are eventually on the chopping block as well, so in reality the big 3 have a challenge in the sense, none of the refrigerants they use have a certain future. I'd like Trane to go high speed because I want their compressors to get smaller