Well, since I'm the one who said in this thread 'with gas prices the way they are' I will take it upon myself to be the one to answer you, regardless of the fact that I drive a V6 Mustang and want only a V6 Camaro. First of all, higher octane fuel does not increase miles per gallon in your car. The closest thing to that even being true is that if your engine is tuned to use a higher octane fuel, it will - over time - get damaged from using lower octane fuel and thus reduce fuel efficiency.
However, you want the people who are, in your mind, being cheap on gasoline prices to do the math and recognize that higher octane fuel would only cost, in your statement, $5 more than regular. Well, I would like you to do the real math, though not with any specific numbers. Consider that gasoline is used not only in your personal car, but also the car that brings the goods to your local publix. Well, the gasoline prices are increasing, and the suppliers are not going to want to earn any less money, so they had a higher gas surcharge onto the super market for their orders. Well, I can assure you Publix does not wish to make any less money, so their prices are going to go up to reflect the further charge on them. At the same time, your personal income isn't changing, because all firms are feeling the effects of oil spread out through them and costs are increasing on them. So, you, as both a consumer and a worker for one of these firms have less disposable income on which you can spend for luxury items. Is gasoline for a higher octane really worth you not going out to eat that one night a week that you normally do?
Which leads me into a further example, because honestly I'm a little peeved at what I percieved as an attack on the logic of my statement before. My parents own a small Italian restaurant in Ormond Beach (which is north of Daytona). The aforementioned gas surcharge is also charged on their restaurant by our suppliers. Not only that, but the suppliers are also enforcing a minimum order value due to the increasing price of gasoline. So, this causes the restaurant's costs to heighten. The obvious recourse is to increase prices, right? Well, with business already down, an increase i nthe price of the restaurant's food would likely lead to a further drop of customers. Customers to not come unconditionally, because theyare the same consumers paying more at the supermarket and gas pump as well. Therefore, the restaurant - and by ownership, my parents - have less disposable income than they are used to.
But, by all means, chastise the people who don't wish tospend an extra $5 at the gas pump, which according to math become $260 on a year, if you only fill up once a week. You can still go and fill up with premium gas, but most people are just trying to hold onto their slice of the American dream by cutting corners here and there.