As I have a Bernina....I copied this advice from the Bernina website:"Always use the original oil supplied by BERNINA. It is a high-quality, resin-free and acid-free oil with the right consistency. If you finish the oil supplied, you should buy a new one from your BERNINA dealer.
If you use cooking oil, you will do more harm than good to your sewing machine because the oil turns into a thick, sticky mass after application, meaning that the hook can no longer run smoothly and easily. We do not recommend any other machine oils from retailers or online stores.
Important:
The consistency of the oil varies slightly depending on the hook, so the oil for the BERNINA hook should not be used for rotary hooks, for example. If you also have an overlocker, the oil for this is different from conventional sewing machine oil."
I have invested enough in my machine to follow this advice as oil really does last a long time.
The other machine I have is Viking....but it does not require oiling at all
On my long arm I do use a different sewing machine oil then on my Bernina