The pumps at a gas station I often go to are labeled ‘Unleaded’, ‘Unleaded Plus’, and ‘Super Unleaded’. When will this madness end? Why in the world are we still calling gasoline ‘unleaded’? Why did we ever call it that in the first place?
First of all, lead (in the form of tetraethyl lead, a lead atom with four ethyl ligands so that it will be soluble) is a gasoline additive. It was added as an anti-knock agent to help boost octane ratings. So conceptually, there are two kinds of gasoline: those without lead added (‘regular’) and those with lead added (‘leaded’); not ‘leaded’ and ‘unleaded’. Calling regular gasoline ‘unleaded’ is like calling it ‘un-uraniumed’ or ‘un-Cheez-Whizzed’. There are billions of things that have not been added to regular gasoline, so why call it by the name of one specific thing that was not put into it?
Second, leaded gasoline began to be phased out in the US in the early 1970’s. That was almost 40 years ago. It has been illegal to sell leaded gasoline for road use since January 1, 1996. That was nearly 15 years ago. But yet the gas pumps are still labeled ‘Unleaded’, ‘Unleaded Plus’, and ‘Super Unleaded’.
These names are bad choices for another reason: the ‘Plus’ and ‘Super’ modifiers could be interpreted as describing the level to which lead has been removed from the gasoline. ‘Unleaded Plus’ sounds like it has had more lead removed from it than ‘Unleaded’ gasoline and ‘Super Unleaded’ like it has had even more lead removed than ‘Unleaded Plus’. In fact, none of the products contain any lead. The modifiers are actually describing the octane rating of the gasolines, not how thorough the ‘unleading’ process was (since there is no ‘unleading’ process).
Frankly, I don’t understand what’s preventing gasoline retailers from changing their labels. The cost of switching is relatively small – just change the labels on the pumps. I’m not certain what exactly the benefits would be: ceasing to confuse any customers who might think that the gasolines actually do still have residual lead in them; ceasing to remind people that burning gasoline used to spew lead vapors into the environment; and just allowing logic to triumph over legacy for once, I guess.