What to do with a lot of old cooking oil?

If you don’t mind working with lye, you could use it to make soap. There are about 6.9 million websites that show how.

Is it Wesson oil? If it is, do not use it in an orgy. You’ll never get rid of it, because it all comes back except one tablespoon.

Olive oil, which seems to be what the OP mostly has, goes rancid fairly quickly even when unopened. He says it’s “years” old, so I’m betting it should just be tossed.

Give it to your local sheep rancher. They’ll know what to do with it.

No local sheep ranch? Throw it away. Too small a quantity to bother with.

Lots of Tiki Torches in summer ! Buy a length of burning wick, and maybe some citronella oil to make your oil smell good and ward off musquito’s. You can use up all sorts of old containers and make gifts of them.

If they have security cameras that catch your car’s license plate, they might call the cops. An animal shelter I near us set up cameras to catch the plates of people who abandon animals, which is a specific crime.

“Wasteful,” in the sense that throwing it away represents a possible lost opportunity for someone else, is one aspect. The other is the cost incurred, i.e. your trash hauler has to pay to get it to the landfill, and then it takes up precious space in the landfill that might be better used for real trash.

I agree with those who suggest handing it off to a local biodiesel producer. They may not pay you for it, but this will keep it out of the landfill; that alone makes this a better option than putting it in the trash.