A cornerstone of U.S. environmental policy has been the reduction of harmful tailpipe emissions from cars and trucks. Thanks to EPA regulations of mobile sources, air pollutants have been reduced by millions of tons in the urban environment. Several EPA fuel regulations have concerned octane. Octane is a gasoline additive that is needed for the proper functioning of modern engines. Octane sources have taken many forms throughout the years, both renewable and petroleum-based. They include lead, methyl tertiary butyl ether (MTBE), benzene, toluene, ethyl-benzene and xylene (BTEX), and ethanol (a biofuel). As adverse health and environmental consequences have been discovered for lead and petroleum-based octane providers, they have been removed from the fuel supply or decreased.
This actually is a better article about the history of octane boosters in gasoline. ⛽
In terms of its octane rating, ethanol has a rating of 113. As mentioned above, fuels with a higher octane rating reduce engine knocking and perform better. Also, almost all gasoline in the US contains 10 percent ethanol. When you mix 10 percent 113 octane ethanol with 85 octane gasoline it increases the octane two points to the normal 87 octane most consumers use. So the higher the ethanol content, the higher the octane. The octane rating for E15 (15% ethanol) is 88 octane and E85 (85% ethanol) is 108 octane.
This map shows major crude oil pipelines in the United States. Layer includes interstate trunk lines and selected intrastate lines but excludes gathering lines. Based on publicly available data from a variety of sources with varying scales and levels of accuracy. From the US Energy Information Agency. https://www.eia.gov/maps/layer_info-m.php
With the global economy in a pandemic-induced coma, the world just doesn't need a lot of oil.
But oil is still flowing out of wells, and with nowhere else to go, it's filling up the world's storage tanks. The oversupply is so intense that this week U.S. oil prices briefly went negative.
But why is that oil still flowing, anyway? Why don't producers turn off the spigot when demand falls?
The short answer is that production is decreasing — just not fast enough.