You just brought up a VERY debatable topic, so you will probably get people from both sides of the fence to post.

Some people swear by the thick stuff while others won't ever touch it. I am the latter.

The engine should not run sluggish with the thicker oil, however, it takes longer for thicker oil to reach critical components on startup, where the vast majority of engine wear occurs. I live in the Pacific Northwest where we have fairly mild temperatures. I run the go to 22R oil, 10W-30. I don't see a point to go with oil that thick, personally.

22RE Performance also does not recommend 20W-50 for any climate. They are located in Chico, California.

I am sure others will have the opposite opinion.

 

There are trade offs between viscosity, pressure and volume.

Typically,
Viscosity gives more shear strength, clings more to parts, it reduces flow but increases pressure.

Pressure is good, over pressure is bad you can trigger the filter by pass and dirty oil isn't something you want on in tight tolerances.

Volume is king, it gives more cooling power, gets where it needs to be quickly.

Your typical modern car will use a 0-5w cold spec. This gives the tight tolerance parts lubricant quickly. They also tend to have higher pressure specs, which actually translates to more volume or rather is a function of the higher pump output volume.

If you have large tolerances at the pump and in the bearings a heavier oil can make up for this, or some of this.

I have no clue really, run what works best for your engine and climate.

 

Define Sluggish ?? We are talking about a 22re here.

I got a sweet deal on a 55 gallon drum of 20/50 Castroil about 15 years ago.

Now Eastern Pa has mild winters seldom Below 0 F for days on end.

I ran 20/50 in all my 22r series engines from high mileage with compression so low I could turn the engine over with one hand on the crank pulley to ones freshly rebuilt.
For a good 15 years .

Personal Choice

 

California is a pretty big state, most of SoCal doesn't get very cold, parts of Central Cal can get quite cold, NorCal can get very cold.

There is nothing in your signature line indicating which vehicle/engine you have.

The others have given some good basic info.

 

So, if I told you I was running olive oil in mine the first thing you would say is "why?"
So, why are you running 20/50? did you buy a lifetime supply like Wyoming or do you have low oil pressure and are trying to help that?
If there is no particular reason then you should probably stick with recommended viscosities.