I'm no gearhead like my father, but to my knowledge gasoline more often than not contains lubricants and other additives (lead!!) which help your engine run. This would not be good for extracting spice! There's also the possibility that parts of it are soluble in water, which would ruin everything.
Perhaps you have gotten your hands on a very clean gasoline, though, in which case it could be a great experiment. If the yield is bad, you can always hang on to the soup and pull with something else.