Analysts also say U.S. petroleum products are probably slightly more expensive because of the export market, but it's hard to say how much. While refined products can be exported, raw crude oil cannot be.

"If the U.S. did not allow petroleum product exports, you would have much lower petroleum prices here at home. You would lose refining capacity but you would have lower prices domestically and you would have a higher price internationally," said Francisco Blanch, head of global commodity and asset allocation research at Bank of America Merrill Lynch.

"There are a number of reasons that U.S. refiners are very competitive. The fact that crude cannot be exported is one of the reasons," Blanch said. Refiners are also using natural gas that is less than $4 per million BTUs in the U.S. compared with $10 in Europe or $16 to $17 in Asia, he added.

John Kilduff, oil analyst with Again Capital, said prices for diesel and crude are higher because of the ability of U.S. refiners to meet some of the demand from abroad.

"The U.S. was the breadbasket to the world. Now we're the refiner to the world," he said.

Blanch said he expects gasoline demand in the U.S. to drop fairly dramatically over the next 15 as years as drivers switch out of old cars, and new cars become ever more fuel efficient.

"In some ways, it's a good thing the U.S. is exporting this. It is improving the balance of payments of the U.S.," he said. Blanch said the U.S. move toward energy independence also gives the U.S. a growth advantage over Europe and Japan. The latest trade data for the second quarter showed a rise in exports and a drop in imports of refined product, helping to narrow the trade gap.

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"We calculate that it may lead to as much as 1.5 percent of GDP additional output for the U.S. relative to Europe every year, as long as the current natural gas price differential persists," Blanch said.

Lipow said if there were no exports of refined product, consumers would be paying the price of a less healthy refining industry.

"If we didn't export this stuff we would simply shut down refineries, and prices may or may not be higher or lower than they are today, but we would certainly lose capacity," he said. "If we were to shut down those refineries, they get shut down forever, so if other refineries were offline, there'd be no slack in the system and we would end up with gasoline shortages."

—By CNBC's Patti Domm. Follow her on Twitter @pattidomm.