PROVIDENCE, R.I. – As Gasoline prices vary widely across the United States, but why gasoline prices vary so widely can be confusing to consumers, the Providence Journal reports.

The U.S. Energy Information Administration (EIA) points to differences in taxes, distance from supply, environmental regulations and competition among gasoline stations as reasons for the price divergence.

Distance from supply has a big impact on prices. For example, stations farthest from the Gulf of Mexico, where nearly half of the U.S. gasoline is produced, tend to have higher prices, EIA says. Also, environmental regulations play a larger role in some states, such as California, where dealers have to offer a unique blend of gasoline to meet the state’s clean-air requirements.

Beyond those factors, pricing strategies among gasoline dealers, as well as the dealers’ own costs, cause price variances, Jeff Lenard, NACS spokesman, told the newspaper. About 80 percent of all gasoline is sold by convenience stores, he said.

“The highest price on the street isn’t necessarily making the most per gallon,” Lenard said. Some dealers may have lower costs than others because of the amount of gas they buy and whether they can rely on sales of other items, such as coffee or sandwiches, for profits, he said.

However, the typical gas retailer does not reap the benefits from the record high profits recently recorded by some big oil companies. Lenard pointed out that only about 3 percent of convenience stores that sell gasoline are owned by major oil companies; the rest are either “unbranded” stations or those that have an agreement with an oil company to sell their brand of gas.