There are a couple of different ways to discover the answer to this question, but here is one way to estimate it. If you look at a page like this one, it shows that the United States consumes about 18 million barrels of oil each day. If you look at a page like this one, you find that a barrel of oil (which contains 42 gallons or 159 liters) will yield something like 19 or 20 gallons (75 liters) of gasoline. Therefore, in the United States, something like 360 million gallons (1.36 billion liters) of gasoline gets consumed every day. That truly is an amazing amount of liquid, but when you consider that there are about 100 million households in the United States, it is only 3.6 gallons per household per day. Each family doesn't consume that much, but a huge number of families are doing it.
In a year, therefore, the U.S. consumes about 131 billion gallons (almost 500 billion liters) of gasoline!
There are two ways we typically see oil and gasoline moving around: tanker trucks and oil tanker ships. A tanker truck can typically hold about 2,500 gallons (9,450 liters) of gasoline. Therefore it would take 144,000 tanker trucks to carry this much gasoline. A large tanker ship like the Exxon Valdez carries about 1.26 million barrels of oil, so it takes about 14.25 of these ships to carry all of the oil that the U.S. consumes in one day.
Where does all of that gasoline go? When it burns, it turns into lots of carbon dioxide gas. Gasoline is mostly carbon by weight, so a gallon of gas might release 5 to 6 pounds (2.5 kg) of carbon into the atmosphere. The U.S. is releasing roughly 2 billion pounds of carbon into the atmosphere each day.
One thing that's been in the news lately is the U.S. Strategic Petroleum Reserve. It currently stores about 570 million barrels of oil in underground salt caverns along the Gulf of Mexico. Given that the U.S. imports about half of its oil, the Strategic Petroleum Reserve holds about a 60 day supply of oil if all imports were suddenly cut off.
Here are several useful links: