Why type of lubricant does a hybrid system use?

Special electrically insulating refrigerant oil is used to keep voltage from leaking to the compressor case through the oil. According to the hybrid manufacturers if even a small amount of another oil is introduced into the system, it may significantly decrease the electrical insulation properties causing compressor damage. The introduction of the wrong oil can cause a diagnostic trouble code that disables the air conditioning system.

Hybrid vehicle makers also warn that if the wrong oil is introduced into, and circulated through the system, all of the main A/C parts (such as the evaporator, condenser, receiver/drier, and compressor) must be replaced. They recommend a dedicated manifold gauge set be used when charging the system to ensure that any residual refrigerant oil left in the manifold gauges from refrigerant recovery on other vehicles does not enter the air conditioning system and deteriorate the insulating performance of the special oil. Our HYB-1 and HYB-2 meet the OEM criteria for hybrid A/C lubricants.