A proprietary refrigerant, called Ikon®-12, was evaluated as an alternative to HFC (hydrofluorocarbon)-134a for automotive air conditioning. The evaluation was motivated by concern over the relatively high global warming potential of HFC-134a. In preliminary tests. Ikon®-12 was found to be compatible with a polyolester lubricant and engineering materials. Refrigeration capacity and efficiency for Ikon®-12 compared favorably to those for HFC-134a. In a preliminary durability test, Ikon®-12 refrigerant showed no significant chemical breakdown after extended operation with an elevated compressor discharge temperature. Further testing would be required to determine if stability and materials compatibility are acceptable for long-term use.