I have a Moparbud, frugile.... he gets used ATF, strains it thru a paint filer and burns it in his 12 valve Cummins.
I'm frugile (cheap?) but I have not arrived quite there yet.
My friend Freddie goes around to all the eatin joints in town and collects their used french fry grease and burns it in his Powerstroke. Smells like french fries when he rides by.