Topping up the tank, we will need to decide which fuel to pump. Typically, in Malaysia, there is Diesel and Petrol. Diesel comes in one formulation, so we don’t have to discuss that here. Petrol though, while it may have different names given by the various brands, comes classified in RON 95, 97 and 100.
What these numbers signify is the amount of Octane, a chemical component of gasoline. The higher the number, the higher the amount of Octane found in the fuel. The higher the Octane number, the more expensive will the fuel be too. Octane affects a vehicle's performance and efficiency; It is a colourless, volatile hydrocarbon.
Octane is obviously important as it is being used to distinguish the different qualities of fuel. This is what it actually does: in an engine, the piston moves up and down whereby the fuel / air mix will be ignited when the piston reaches the top point. This explosion forces the piston on its next round to come back to the top position for the next ignition. In order for this to work, the ignition needs to be happening at a point in time that accelerates the piston on its way. Should the ignition happen before the piston reaches the top point, it would slow down the piston.
High pressure and heat in the piston chamber can lead to a pre-mature ignition. And this is where Octane comes in by preventing such early ignition. Octane ensures that the fuel will be ignited at the right time. Depending on the engine and car type, engines may run at higher RPM (Revolutions per Minute). Some cars have higher pressure in the combustion chamber, run at higher RPM and use more fuel, thus generating more heat. Sports cars and performance cars would fall into this classification. Such cars should use fuel with higher Octane.
The car manufacturer would recommend the correct fuel for any vehicle. German Motors staff would often be asked if one can use fuels with different ratings than recommended. The simple answer is that one should stick with the recommendation made by the car manufacturer. One could upgrade but should never downgrade. Using a fuel with a lower RON rating than recommended may over time damage the engine.
One will easily find a fierce debate going on online about the benefits of using higher RON fuel. Many claim that the fuel would be more efficient and that the engine would run smoother. If this is the case is hard to say as fuels contain a lot of other additives to keep the engine clean, cool, and valves free from deposits. A more expensive fuel may not just contain more Octane, but also additives that are not found in the lower RON fuels. Therefore, it may not be easy to trace back an improved performance to the increased presence of Octane alone.
Did you know?
Did you know that RON stands for Research Octane Number and signifies the amount of Octane in the fuel, which has to meet specific requirements, as scientifically measured.
