Your typical WW2 tanker ran between 10,000 and 15,000 tons, with a few as large as 25,000 tons. There is about 7 barrels of oil to the ton, so you are looking at somewhere between 70,000 barrels to 175,000 barrels per tanker. Much of the oil in tankers that were sunk was refined products, chiefly gasoline (motor and higher octane aviation gasoline), diesel, and kerosene. That tended to burn quite nicely when torpedoed. The Japanese did use raw crude oil from some of the Indonesian fields that was of sufficient high grade to burn directly as boiler fuel, and did have problems with the accompanying vapor explosions, such as the one that destroyed the carrier Taiho. Refined products are considerably less toxic than raw crude, which can range from high-quality West Texas oil to the high-grade sludge produced by Venezuela. Raw crude contains the full spectrum of oil products in varying amounts, along with a host of contaminants such as sulphur, various metals, bromine, methane in solution, waxes of various kinds, etc. A refinery is typically optimized to refine a given type of crude, and will actually produce more than a barrel of products from a barrel of crude as a consequence of the adding of hydrogen to the heavier high-carbon crude fractions to produce lighter fractions such as gasoline, kerosene, and diesel oil which take up a larger volume than the high-carbon fractions.
The tanker losses in WW2 were spread over the entire ocean area of the world, and over a period of 7 years, and occurred as one time events for the area the ship was sunk in. Much of the oil was refined products. What you have in the Gulf presently is a concentrated spill in both location and time, with continuous effects on the environment. It is not a one-time event, but a continuous stream of oil hitting the wetlands, marshes, beaches, and ocean bottom. Based on the Exxon Valdez spill, the long term effects are not going to be known for several years or possibly decades. The Gulf ecosystems that are being effected by the oil are likely never to return to a pre-spill state, or if they do, it will be many decades in the future.
Very insightful thank you,