I don't know the real answer, but using basic math I have come up with something that is likely close.
America uses 22 Million barrels of oil a day. A barrel contains 42 gallons and produced 44.2 gallons of refined product. 19.5 gallons which is gasoline.
So, 22 million times 19.5 = 429,000,000
But, the US also imports gasoline daily because we can not refine enough to meet demand. So, I estimate the answer to be in excess of 430,000,000 gallons a day.