I would the store the oil, although the small amount involved wont go that far, its still better than not having it!

As well as use as heating fuel, small amounts of waste oil are useful for lighting fires of coal or wood if kindling is not available, much safer than useing gasoline or kerosene, which would likely also be in short supply.

Also used motor oil is useful as a lubricant for low tech purposes, especialy if WD40 or "3 in one" oil are in short supply.

Another use is to apply it to saw blades, files and other tools to prevent rust, especialy on items not in regular use.