Considering a new leak detector? Make sure it works on HFC and HFO gases. Image courtesy of Yellow Jacket
A third gas presented as an alternative is the one that eventually won out: R1234yf, also known as HFO1234yf. With a GWP of <1 (according to the United Nation’s Intergovernmental Panel on Climate Change), it certainly meets the requirements of the European Union directive. Its pressure/temperature characteristics also are close to that of R134a, making it almost a “drop-in” replacement.
Naysayers at first pointed out that R1234yf is also flammable — albeit “mildly flammable” — but numerous tests performed by automakers and SAE Cooperative Research Projects have proven time after time that the refrigerant is safe for use in automotive A/C systems. Though behind schedule and past the deadline required by the MACS Directive, the first cars equipped with R1234yf were sold in Europe in March 2012 (as reported in the European Fluorocarbons Technical Committee newsletter).
Remember, the EU MACS Directive only applied to vehicles built for sale in the European Union countries. No other country in the world, including the U.S., had made any indication that it would follow suit. There was and is, however, a huge incentive for domestic manufacturers to make the switch. It’s called CAFE, or Corporate Average Fuel Economy, and it is the fleet fuel efficiency mandates issued by the Federal government.
Currently, CAFE standards require that the average fleet fuel economy for cars and light trucks meet or exceed 54.5 mpg by the 2025 MY. That explains the growth of hybrid and diesel offerings, and the renewed interest in hydrogen fuel cells. But even that may not be enough for some manufacturers, who need to earn or buy “credits” they can use to offset the mandate. Some companies, like Tesla, have an abundance of credits and sell them to other manufacturers like product. Alternatively, credits can be earned by using green systems, and HFO1234yf air conditioning systems qualify.
GM was the first American company to add R1234yf systems to its product lines, specifically the Cadillac XTS, and has plans to expand the use over time to all their models. Chrysler has since announced that it, too, will be making the move (not all at once, but over time) on its lineup. Asian manufacturers have already added some models to their North American market offerings utilizing the new gas.
But one of the very first carmakers to produce an HFO1234yf-equipped car for sale in the U.S. was Mercedes-Benz (Daimler). Certain 2013 SL-class models arrived equipped with 1234yf systems (made in late 2011/early 2012). That was, however, going to lead to a firestorm in the industry later that same year.