us started putting ethanol in gasoline in the late 1970s.
when did the us start putting ethanol in gasoline?
the late 1970s
e20 contains 20% ethanol and 80% gasoline, while e25 contains 25% ethanol. these blends have been widely used in brazil since the late 1970s. as a response to the 1973 oil crisis, the brazilian government made mandatory the blend of ethanol fuel with gasoline, fluctuating between 10% to 22% from 1976 until 1992. due to this mandatory minimum gasoline blend, pure gasoline (e0) is no longer sold in brazil. a federal law was passed in october 1993 establishing a mandatory blend of 22% anhydrous ethanol (e22) in the entire country. this law also authorized the executive to set different percentages of ethanol within pre-established boundaries, and since 2003, these limits were fixed at a maximum of 25% (e25) and a minimum of 20% (e20) by volume. since then, the government has set the percentage on the ethanol blend according to the results of the sugarcane harvest and ethanol production from sugarcane, resulting in blend variations even within the same year.
common ethanol fuel mixtures
after reaching more than four million cars and light trucks running on pure ethanol by the late 1980s, representing 33% of the country's motor vehicle fleet, ethanol production and sales of neat ethanol cars tumbled due to several factors. first, gasoline prices fell sharply as a result of the 1980s oil glut. the inflation adjusted real 2004 dollar value of oil fell from an average of us$78.2 in 1981 to an average of us$26.8 per barrel in 1986. also, by mid-1989, a shortage of ethanol fuel supply in the local market left thousands of vehicles in line at gas stations or out of fuel in their garages. at the time ethanol production was tightly regulated by the government, as well as pricing of both gasoline and ethanol fuel, the latter subject to fixed producer prices. as a complement, the government provided subsidies to guarantee a lower ethanol price at the pump as compared to gasoline, as consumers were promised that ethanol prices would never be higher than 65% the price of gasoline. as sugar prices sharply increased in the international market by the end of 1988 and the government did not set the sugar export quotas, production shifted heavily towards sugar production causing an ethanol supply shortage, as the real cost of ethanol was around per barrel. as ethanol production stagnated at 12 billion liters and could not keep pace with the increasing demand required by the now significant ethanol-only fleet, the brazilian government began importing ethanol from europe and africa in 1991. simultaneously, the government began reducing ethanol subsidies, thus marking the beginning of the industry's deregulation and the slow extinction of the "pró-álcool" program.
history of ethanol fuel in brazil