The OP might be a newbie to saws (I question even this, considering that he owns saws "20 to 30 years old"), but my hunch is that he or she is not new to the Internet. Coming onto AS and asking what oil to use -- without first doing a search - is like going onto a car repair forum and asking, HOW DO I CHANGE MY MOTOR OIL??? without first doing a search.
Considering that it's probably one of the most commonly-asked questions on the forum, not doing a search first is the equivalent of saying, "My time is more valuable than yours, so please explain it again for the 250,000th time this week, because I'm too busy to do a 5-second search."
I doubt the OP meant it to be rude, but that's how some people see it. Hence my humorous memes suggesting that a search might find some answers.
No worries brother.
I knew the OP said he had some older saws. I saw this and originally thought that maybe he inherited them from his dad or grandpa or something, so it didn't matter to me.
I got my first saw at age 30 when I went to a good dealer back in 1994 and they didn't have salesmen per se, they had a team of hardware and equipment specialists. It began as a hardware store, and gradually expanded to rentals, then Echo and Stihl dealer and I guess I lucked into my first saw being of decent repute even now some 30 years later. My dealer recommended to me an 026 which came with an 18 inch bar and case. If I remember right, it was under $400 out the door back then. They started me out with Stihl 2 stroke oil and the owners manual. Having only used saws that were some older friends' saws or the one that a landscaper boss of mine had when I as around 18, all I knew about saws, I would learn from my manual, from good safety principals and from knowing when to defer to more experienced arborists if a job was above my experience. As far as 2 stroke mixing goes, I went by the book from Stihl, Echo ( my new 1994 SRM string trimmer), and my Honda and Suzuki dirt bikes.
There was lots of good oil back in the 90's, and as I have learned, many new and better oils out there here in the 2024's.
Thankfully we have resources like these forums and the guys and gals who pass on their knowledge. I know I appreciate everyone, even those who give and take a bit of " the business"
Here is one thing about OIL and OILS that I bet has been covered in some of the plethora of oil threads, but, when I got my first OLD saw. My Mac 200 a few years back, I think I saw that it had markings on it that called for something like 20:1 and SAE30 or something like that. This led me to ask, WHAT should I use in it NOW? Considering today's oil/fuel etc.
YUP, you guessed it, I either asked some Mac guys here or did a search or both.
Here is one answer one guy posted from 2008,
I own a small fleet of McCullochs, including a couple of the big reed engine saws, and I run them all on 40:1 mix. This type of question has probably been discussed literally a thousand times in the chainsaw forum. The reason those old saws used a richer mix was due to the quality of two-cycle oils at that time. Many of the manufacturers' instructions even allowed for the use of SAE 30 motor oil as the mix. Because the two-cycle lubricants have been so much improved since the 50's and early 60's, you can readily use a 40:1 mix today. However, if you feel so inclined as to use the original mix recommendations, go right ahead and be prepared for the smoke cloud!