Here we go again with another replacement refrigerant. This one is called HFO-1234yf, also known as 2,3,3,3- Tetrafluorpropene. Can’t wait to hear the nicknames techs will come up with for this one. For most of the public there will be little difference except they may notice a slight increase in mileage, when using A/C.It has a global # of 4 compared to 1200 for R-134a or a life span of about 2 weeks compared to 10 plus years for R-134a. It is more efficient and is a drop in replacement for R-134a and is also highly stable when compressed. It is claimed that the hotter it is the more efficient it becomes. It is not going to be cheap, $50 + for the average dealer cost for replacement and as of yet no one has built a plant to manufacture it. Most of the present product is coming from pilot plants and until more major manufactures announce, I doubt if any will be built. Several sources have announced that GM will use it in 2013 but I have not seen anything from GM officially. When the plants are opened the chemical companies will try to recoup their investment in a hurry as they don’t know when the next replacement would become available. Plants could be converted to R-134a but have to be built from scratch for HFO-1234yr. It is also slightly flammable, how can something be slightly flammable?This is going to force all shops that do A/C work to use a identifier before doing any A/C work as they should be doing now. No word if totally new equipment will be needed but I would think it will. R-12 was around for years and R-134a was supposed to be the savior for the atmosphere and now HFO-1234ya is the answer. Who are we to believe, is this a scam for the chemical companies to show a profit and will another better product be forthcoming? Why do all the formulas start with caps and end in small letters, and why are the names so confusing, why not call it rip off #1 and #2 and so on?