back in the day.
My brother pumped gas 50 years or so ago and had a length of rain gutter and wires across to hold the oil cans . Right on the main highway and they sold a lot of oil . the final drippings gave him about 1/2 a gallon a day. cars used nore oil in those days. usually it was ask what grade of gasopline and ask if they wanted the oil checked and. if they needed oil , the can drained in the engine while the windows were washed and the gas tank filled. I still collect the last bit of oil. I save a cardboard oil case,. cut off the tops of 6 plastic cans put then in the bottom and turn the fresh oil cans upside down and let them drip. I used the collected oil in squirt cans, for the drill press, lubing farm machinery and my model T speedster. has the flipper oil caps on the front spindle king pins, spring snackles,, etc