I recently did the major fluid changes on tractor and RTV. I went to county s
disposal and told him I had about 8 gallons of used hydraulic fluid. He told me to dump it in with the motor oil? So I did.
stories about old timers painting their barns with used oil, my buddies got 1 his grand dad painted with oil. 100 yeas old and still in good shape.
I only say that because it's what I was told when I dropped my old oil off where they have a waste oil furnace.
I remember when my father used to drain it onto the gravel driveway to keep the dust down... I wouldn't dream of doing that now.