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What is the octane rating in gasoline?

Gasoline is the best-known fuel and has different properties that allow it to be the source of energy that runs the engine of your vehicle.


What is the octane rating?

The octane rating is defined as the measure that indicates the anti-knock capacity of the fuel, that is, the ability to avoid producing a detonation caused by the premature combustion of the fuel in the engine. This index has a unit of measurement between 0 and 100.

In Puerto Rico this is represented by the acronym AKI (Anti Knock Index) which corresponds to the average value of two laboratory measurements, the RON (Research Octane Number, which measures the resistance to detonate in low load cycles) and the MON (Octane Number Engine, which measures the resistance to detonate in high load cycles).


How it is determined:

The octane measurement of fuels is established using an octane number scale. On this scale, iso-octane hydrocarbons (which are low detonators) are given a RON index of 100 octane and n-heptane (which is very detonating) a RON index of 0 octane.

The lower the octane rating, the easier it is for the fuel to detonate under conditions of lower temperatures and pressures. If this explosion is carried out at a time that is not optimal, it could seriously damage some components of the engine, such as the piston, the connecting rod (responsible for connecting the crankshaft with the piston), the jacket, the cylinder head (engine head) and the crankshaft (responsible for transforming the linear movement of the pistons into a circular movement).   On the contrary, if a fuel with a higher octane rate is used, the combustion that takes place in the engine cylinder will be more uniform and therefore, more controlled and effective. 

The octane needs vary from one vehicle to another depending on the technical parameters of the engine (mainly the compression ratio) so for a correct operation of this must be used a fuel with an adequate octane rating. For more information on the ideal octane rating for your vehicle's engine, visit the manufacturer's manual.


TotalEnergies Fuels:

 Our Regular gasoline has an AKI  87 octane, and our gasoline Premium has an AKI 93 octane; none contain lead or manganese. In the case of Excellium Premium gasoline, it contains an additive package composed of detergents, antioxidants, and friction modifiers that provide cleaning properties to our fuels and help your engine as follows:s

  1. It reduces CO2 emissions, which allows you to improve the operation of your engine and emits less CO2.
  2. They remove up to 93% of the dirt in gasoline engines.
  3. Fights oxidation and protects metal components from corrosion

If you have questions about fuels and their properties, write to us. We are here to serve you!