IndyCar Series
For the 2006 season, the fuel was a 90%/10% mixture of methanol and ethanol. Starting in 2007, the league advertised using 100% Fuel Grade Ethanol. The mixture was actually 98% ethanol and 2% gasoline. The additives satisfied the U.S. government's requirement that the alcohol be unfit for human consumption. It also adds a visible color in case of a fire.