When I was 15 I lied about my age and got a job at a gas station working 3rd shift.
That summer, the only time I ever saw anyone buy or use lead additive was one really old dude who put a can in with every fill up.. his car was some mid 70's sedan, that probably didnt need the leaded gas anyway.
I'd like to know how an engine designed to run with leaded is different from an engine designed to run unleaded.. it would also be cool to know what the average octane rating was for gas back in '46 thru '50
