Grant there's been discussions about this on several forums over the years. Actually Tammy just recently did an actual test of different lubes here on QB. Old Singer guys still say vaseline is the best thing to substitute for the original Singer lube. What I've taken away from all the discussion is there is very little heat from the machine itself, so the need is for a low melting point lube.
Confession time. It's been almost 6 years since I got my 201-2. I was a total newbie to working on sewing machines and this was my first Singer. I had read all the discussions at the time and what I recalled that stood out was people were talking about how much better it was to use Tri Flow grease because it stays put on gears. Today I know that's not appropriate in this particular instance but back then I knew nothing. So I went to a hardware store and they sold me a white grease saying it's the same thing as TriFlow. And that's what's still in my 201. Only because I can't get the darned motor off of it to clean it all out and replace the wicks. My pretty Elizabeth is the first machine going to get a complete spa day once my new shop gets built, hopefully soon!
Cari