That FAQ was clearly written by the marketing and legal departments, not the tech dept. If good science supported their claims, they would be happy to show the data. Instead, they serve up some carefully crafted generalities about how some unspecified number of customers haven't complained and about how some duct temperatures might be warmer.

R-134a in an otherwise unmodified W123 won't perform nearly as well as R-12. There are those of us who have already learned that lesson. And others, apparently, still hankering to pay tuition in the school of hard knocks.