In 2003 these limits were set at a minimum of 20% and a maximum of 25%. Since July 1, 2007 the mandatory blend is 25% of anhydrous ethanol and 75% gasoline or E25 blend. The lower limit was reduced to 18% in April 2011 due to recurring ethanol supply shortages and high prices that take place between harvest seasons.here are no longer any light vehicles in Brazil running on pure gasoline. Since 1976 the government made it mandatory to blend anhydrous ethanol with gasoline, fluctuating between 10% to 22%. and requiring just a minor adjustment on regular gasoline engines.