SOCAL - PHILLIPS XC 20W-50 or AEROSHELL W100 FOR LYC IO-360 ?

[DCarlton]

Which oil do most folks prefer now in SOCAL?  Single weight or multi weight?  I've shifted back and forth over the years.  I was happy with W100 but now folks are recommending 20W-50.  I believe my oil pressures are a tad higher with single weight but I'm not sure that really matters if the oil is flowing nicely.  My engine has less than 100 hours SMOH so I'm really curious.  Thanks.  

[N201MKTurbo]

I’ve always used 100W. I will use a multi weight if I’m going some place cold, because I’ve found it starts easier. If you get a pre-heat, then it doesn’t matter.

You are treading more into religion than science.

[toto]

Mike Busch and others have advanced a theory that straight weight oils are better for corrosion resistance in engines that sit for long periods of time. The basic idea is that the oil remains thicker when cold, and protects engine components longer (whereas the multi weight would all drip into the pan and leave components exposed). 

Haven't seen much science on that though. 

Aviation Consumer does a nice oil shootout every once in a while, and the non-Plus W100 hasn't done particularly well on corrosion iirc. 

Ex:

https://www.aviationconsumer.com/uncategorized/14-day-oil-shootout/

[MB65E]

Aeroshell 100+. 
been using it since it came out. I often have the same question, but have found nothing compelling to switch to 20/50. 
The new Phillips victory has the Lycoming additive and is cheaper but 100plus has been great in my book.

Also southwest based,

-Matt