Octane is the resistance to detonation of a certain fuel used in engines in the Otto cycle. The higher the octane, the greater the capacity of the fuel to be compressed, under high temperatures, in the combustion chamber without detonation.
The octane values of a fuel vary, with a minimum index for the proper functioning of each vehicle. Values lower than those established may cause the engine to be destroyed.
The octane index establishes an equivalence relationship to the percentage of mixture in an isoctane and n-heptane. In this sense, a 90-octane gasoline has a detonation resistance equivalent to a mixture of 90% isoctane and 10% n-heptane. In Brazil, the unit of measurement used is the Anti-Knock Index (IAD).
Very powerful engines require fuels with high octane ratings, since the use of gasoline with lower values they will increase consumption, reduce engine power, in addition to triggering problems mechanics. However, it is important to clarify that high octane ratings do not guarantee fuel quality and the best performance of the car, as for this to occur it is necessary to have octane compatibility with the capacity of the motor.
According to data from Petrobras (Petróleo Brasil S/A), the Anti-Knock Index (IAD) of gasoline produced in the country are:
Regular Gasoline: 87%.
Supra Additive Gasoline: 87%.
Podium gasoline: 95%.
By Wagner de Cerqueira and Francisco
Graduated in Geography
Brazil School Team
fuels - geography - Brazil School