I save my old oil in 2.5 gallon laundry detergent containers and when I get around 5 gallons saved take it to the county hazardous waste collection point, nice people, open three days a week, never have to wait more than 5 minute, usually not at all and it's free. I get rid of any other hazardous waste at the same time. They aren't fussy about the 5 gallon/ 50 lb limit if you don't grossly overdo it.