The way Pennsylvania's gas taxes are calculated changes as of tomorrow (January 1). But it's not clear yet exactly what it will cost motorists. The retail tax at the pump is being eliminated as the cap is removed from the wholesale tax, known as the Oil Company Franchise Tax. Retailers could pass all or part of their higher tax to consumers as its uncapped in three phases over the next five years. It could mean up to an additional 9 cents a gallon this year. AAA says market factors could also play a role in whether the entire amount is passed along.