Thick vs thin a/c oil

[dumkid]

Is pag 46 oil thicker than pag 150 oil? Will thicker a/c oil hurt the compressor? I've never found a detailed answer on the internet, and was curious what you guys know.

 

[paulo57509]

PAG (cSt) 150 is thicker than PAG (cSt) 46 (@40C).

You should use the oil specified by the compressor manufacturer. There are charts listing compressor/oils online.

 

[FowVay]

PAG oils have their viscosities listed as ISO numbers. As with all viscosities, the ISO number will correlate to a numerically rated physical viscosity and will align with the mid-point kinematic viscosity. ISO 46 will be a 46 cSt oil at 40ºC on average. Air conditioner systems in automobiles generally use one of three different ISO viscosity grades: ISO 46, ISO 100, or ISO 150.

You can see the kinematic viscosity as measured in centistokes at 40ºC from the chart below. Compare the numbers to get an idea of the difference. As paulo57509 stated, always use the viscosity specified by the compressor manufacturer.