Lower Viscosity of Refrigeration Oil

No

It is far better to drain it out entirely, and replace with the correct grade of oil. Equipment manufacturers can generally walk away from any warranty claims after failure if the wrong grade of oil has been attributed to the warranty call-out.

If in doubt, refer to the equipment manufacturer's operation and maintenance manual, which should have been supplied with the equipment. If it isn't available, start with a phone call to the equipment manufacturer to obtain a replacement as a high priority.

Most people are confused about oil viscosity.Here is a link to a very interesting and informative white paper on oils in general,and tells you everything you need to know about oil viscosity,multi-viscosity oils,single viscosity and why there are different grades of oil.Bob THE Oil Guy really knows his stuff.It is divided into chapters detailing the many characteristics of the different oils.Chapters 2 and 3 are very relevant to this discussion.

No chemistry lessons required,it is written in simple language.

I recommend it to anyone curious about motor oils and lubricants.

Refrigerant oils are especially peculiar and specialized in their characteristics and should not be mixed or substituted.

https://bobistheoilguy.com/motor-oil-103/