Gasoline had many disadvantages as an automotive resource. The "new" fuel had a lower octane rating than ethanol, was much more toxic (particularly when blended with tetra-ethyl lead and other compounds to enhance octane), generally more dangerous, and contained threatening air pollutants. Petroleum was more likely to explode and burn accidentally, gum would form on storage surfaces and carbon deposits would form in combustion chambers of engines. Pipelines were needed for distribution from "area found" to "area needed". Petroleum was much more physically and chemically diverse than ethanol, necessitating complex refining procedures to ensure the manufacture of a consistent "gasoline" product.
However, despite these environmental flaws, fuels made from petroleum have dominated automobile transportation for the past three-quarters of a century. There are two key reasons: First, cost per kilometer of travel has been virtually the sole selection criteria. Second, the large investments made by the oil and auto industries in physical capital, human skills and technology make the entry of a new cost-competitive industry difficult.
Until very recently, environmental concerns have been largely ignored. All of that is finally changing as consumers demand fuels such as ethanol, which are much better for the environment and human health.3