Richard Sheffield, a shop owner and an automotive training consultant based in Waverly Hall, Ga.,says he got good information from a Chrysler presentation on the new R-1234yf refrigerant, which Chrysler is using in its 2014 Jeep Cherokee. Interviewed by Elliot Maras, editor of PTEN Magazine, Sheffield thinks the new refrigerant will be safe and its service will not be too difficult for technicians.