The gas station opened in 2012 and was built to show that compressed natural gas could be used effectively in cars in Afghanistan.
A similar gas station in neighboring Pakistan costs no more than $300,000 to build, according to a report by John Sopko, the congressional-mandated special inspector general for Afghan reconstruction.
That would make the Afghan gas station more than 140 times more expensive.
Sopko says the Pentagon is dodging his inquiries about the $800 million program of which the gas station construction was a part.
In response to questions from ProPublica, a Pentagon spokesman says the appropriate official will be made available for questions.