The price for a gallon of gasoline is on the rise again.
That has many people asking why.
That includes the federal government.
The Environmental Protection Agency called eight top gasonline producers to Washington today to try and get some answers.
The oil companies blame the new cleaner, re-formulated gas which reduces air pollution.
But, the E-P-A isn't buying it.
EPA spokesman Robert Perciasepe said "We don't see these price differentials anywhere else in the US where clean burning gas is being used."
Both the E-P-A and the Energy Department are investigating the price hikes.
The White House says any evidence of price gouging will be turned over to the Federal Trade Commission.