During former Gov. Joe Manchin's administration, lawmakers capped how much the variable component of the gas tax could change each year.
"We put a law in place a few years ago that basically limits the amount of change in the wholesale price to no more than 10 percent change per year," Deputy Revenue Secretary Mark Muchow said.
Muchow said the actual average wholesale price of gas statewide is in the range of $3.13 to $3.16 per gallon. If officials had used the actual price to calculate the tax, it would have gone up an additional 1.6 cents.
"If the wholesale price was $3.16, the variable component would have been about 15.8 cents," Muchow said.
The 1.3-cent increase next year should generate an additional $18 million in revenue for the state road fund, Muchow said.
Retailers were notified of the increase earlier this month, said Jan Vineyard, president of the West Virginia Oil Marketers and Grocers Association.
She said the tax increase didn't come as much of a surprise, because retailers knew the average wholesale price being used by the state was less than the actual price in the wholesale market.
Vineyard's group is sending out new decals for gas pumps that detail how much consumers pay in taxes per gallon.
"We like to put those on our pumps because I don't think people realize how much we are taxed," Vineyard said.
West Virginia already had the highest unleaded gas tax among surrounding states. Once the increase goes into effect, only Pennsylvania diesel fuel users will have a higher tax rate.
While Pennsylvania charges a lesser tax on unleaded gasoline, the state charges a 39.2-cent tax on diesel fuel.
Contact writer Jared Hunt at jared.h...@dailymail.com or 304-348-5148.