Reply #74: Motor oil != crude oil.

[Statistical]

Pour a gallon of gasoline on your driveway and then wait 100 days. Let me know how much remains. While 100% won't be gone but 99%+ will. If you look closely some of the heavier components due to imperfect refining will remain as a stain.

Crude oil is what spilled in the Gulf not a billion qts of Penzoil 10W-30.

Crude oil is a mixture of various petroleum products. It isn't a single entity. Many of the components (like gasoline, benzene, butane, propane, Naphthalene, Kerosene, Hexane, etc) are very volatile and don't survive very long. Some of it (components used it make asphalt and heavy oil do).

75% is comparable to other major spills. The lighter components will evaporate very rapidly. Now just because 75% is "gone" in 100 days doesn't mean 100% will be gone in 150 days. It doesn't work that way. What remains is the heavier harder to break up stuff. It will be broken down by microbes and other natural processes more slowly.