You are correct about the - 40c miscibility problems . the oil has to have a low pour point in order to flow and still have sufficient viscosity for the compressor lubrication 你谈到油在40度的溶解性的问题是正确的。油不得不具有有一个很低的流动点(流(动)点:油或其他液体在规定条件下流动的最低温度) ,还需要有足够的粘度作为压缩机的润滑作用。