Supertanker capacity varies, but Wikipedia says most carry about 2 million barrels. The largest tanker in the world is a ship we've talked about before -- the Jahre Viking (now called the Knock Nevis). It carries 4 million per day. So, it takes 10 --normal-sized-- supertankers to supply the U.S. with oil for a single day.Oct 17, 2007read more >>