Please advise me.

What kind of oil should I use for a 1/3 hp electric motor?

The motor bearings have oil ports.

Can't I just use regular automotive motor oil? Would gear oil be better?

It's the fan motor for my electric furnace (squirrel cage). The original
1/3 hp motor blew up. The furnace guy insisted I put a 1/4 hp motor in, but
the capacitor blew and the 1/4 hp motor blew up. I had a surplus 1/3 hp
motor I bought. It turned in the wrong direction so I reversed the stator.
It worked ok all last winter but I want it lubed up for next winter. The
biggest problem is keeping the wires away from the fan blades because the
stator is reversed, but I've got them tied back pretty good. Jon