This pricing mechanism is no longer applicable given the costs of a gallon a gas and should be abolished.
According a a MarketPlace.org article at http://www.marketplace.org/topics/business/ive-always-wondered/why-do-ga...
"You won't find tenths of a cent on your credit card bill. Or even on the pump. But if you buy 15 gallons of gas at $3.299, you’re paying 13 cents more than at just $3.29. Since Americans buy 178 million gallons of gas a day, that’s a half-billion dollars more per year."
This ends up being yet another subsidy for gas industry that continually report record profits at the expense of consumers. This change has to be made at all gas stations in order to be fair and requires no new technology.