I've always been curious if the red dye is put in at the fueling rack at a refinery or if it's put in at the distributor.
Sort of like the odorant in propane. I know way back when, the stink was added at the distributor but now it comes with the propane when it's loaded at the fuel rack.
Interesting story abut that... One of my good friends and hunt buds owns the local propane company up town (I buy my gas from him) and when he was much younger, he caught his girlfriend cheating on him so he took some of the concentrated odorant and dripped it in her other boyfriend's car and turned out he had to sell the car to get rid of the stink... Talk about payback.. There it is.
Think it called Methyl Mercaptan or something like that. All I know is it stinks terrible.