How to lower gas prices

I am not sure why the gas companies would do this--and I am certainly against the government mandating it--but what if they stopped making mid-grade and premium gasoline?

Even when the price of crude per barrel falls we can't gain ground on pricing because of refinery capacity, so why not stop devoting 15-20% of that capacity to fuel that our cars don't need anyway?

If there were more low-grade gas on the market--the type recommeded by the vast majority of auto manufacturers--wouldn't that increased supply lower the price?

Just wondering.