Brazil, the world's largest producer of sugar cane ethanol, introduced a 5 % blend to gasoline in 1931, increased to a range of 10 % to 15 % in the 1970s and today it is 27.5 %.
The progressive increase in the percentage was carefully studied, including its possible effects on durability and performance on the vehicle fleet and distribution infrastructure. Adding the mandatory blending to the sale of pure ethanol directly to the consumer at service stations, under free market conditions, Brazil currently replaces 45% of its gasoline demand.
Studies endorsed by the Brazilian Association of Motor Vehicle Manufacturers (Anfavea) show that levels of 5 to 10 % ethanol do not require any modification to vehicles and do not bring any harm to their performance. On the contrary, they naturally raise fuel octane and increase engine torque.
Brazil, with a favourable climate, develops and markets vehicles capable of operating on any ethanol blend up to 100% hydrated ethanol (E100), however, as pure petrol has not been sold in the country since 1993, Brazilian flex vehicles actually operate on any ethanol blend from E20 to E25 up to E100. To avoid cold weather starting problems, flex vehicles manufactured in Brazil featured a small auxiliary tank that stores petrol and was injected for cold starting when the ambient temperature is below 15 °C. The third generation flex engines launched in 2009 make it possible to dispense with the auxiliary tank for cold starting.
In Brazil there are currently 4058 filling stations with e85 or e100 ethanol supply.