you can also make a leaded 100 octance fuel by putting regular in it and adding 1 oz or about a capful of rubbing alchohol per gallon.

I think that it's unecessary to run premium in cars that don't need it. Some cars do need it aka higher compression ratio cars. Just like you can't or at least shouldn't use 83 octane in a car with 15:1 compression ratio in a fully built race engine. it's just not logical and potentially hazardous to the engine.