On Jun 9, 3:24*pm, J Burns wrote:
A decal on my furnace blower seemed to say the motor was permanently
lubricated. *The other day I got my head a little lower and saw a second
decal saying it should be lubricated every couple of years with 20W
nondetergent oil.

I think 3-in-1 is like that, but I can't find my can. *I did find a
4-ounce container of Marvel Lubricating Oil. *Among the uses listed on
the label is "small electric motors."

Small is relative. *Would Marvel Lubricating Oil be good for a furnace
blower?

I'd say it's a bit thin. My walmart has 30wt nondetergent. I'd
probably lean that way if I couldn't find 20wt. Nondetergent also
gets used in things like pressure washers.