By eliminating the use of both premium and unleaded fuel cost on refineries, lesser down times. Using Mid grade is no better than the use of premium and unleaded beside being highly costly to the producer to make.
There is no car on the market that can't use mid grade gas, gas is gas, it burns violently, and in cars would be better for both the poverty level guy and those with deep pockets. With one fuel we could possibly eliminate the use of ethanol, as there wouldn't be the need for it as there is currently. Then corn can be what is supposed to be, food and corn based food base. there will be people that will complain that I need this fuel to run well, Well folks there is no difference in what fuel you use. At 55 mph if you have a car that does 65 mpg on unleaded you will get 65 on mid