Thursday, March 03, 2011 5:10 PM
Your RON questions answered
Can a car using a higher than recommended RON (Research Octane Number) experience a difference in performance?
It's a common question motorists often asked. Who better to answer it than an expert in the oil business.
According to Shell, it really depends on the car and its engine condition. If a car has knock sensor (as most cars do today), "it will adjust to the mid-point of the sensor's operating range."
Role of knock sensor
A knock sensor basically ensures that the car is extracting as much power and fuel economy as is possible from the engine.
Older cars tend to have carbon build-up in the combustion chambers. When they are hot, they can cause pre-ignition, so using a petrol of higher RON rating will check such uncontrolled explosions and improve the engine performance to some extent.
And as cars have varying degree of deposits in their engines, the amount of performance improvement varies from car to car.
Uncontrolled explosions or knocking is a no-no in combustion as it wastes energy and can cause engine damage.
A knock sensor allows the engine to run with the ignition timing as far advanced as possible.
The computer will continue to advance the timing until the knock sensor detects pinging. At that stage, the computer retards the ignition timing just enough for the pinging to stop.
Match RON and engine
Petrol with a higher RON rating will deliver better performance and better fuel economy in engines that are designed for such a fuel. The combustion in these engines will release more energy from the fuel as a result of higher compression in the combustion chambers
However, RON as a measure of a fuel's tendency to burn in a controlled way, cannot be seen in isolation. It should be considered in tandem with the fuel addtives and the engine technology. In addition, modern additives can help to lower fuel consumption.
Cars equipped with knock sensors are able to adapt to fuels that have slightly lower RON than the minimum specified for the cars. The sensors will allow the engine to adapt to the lower RON but the car will use up more petrol and lose some power as well.
Mixing 'em up
Mixing RON95 and RON97 does not have any detrimental effect as long as the fuels meet or exceed the minimum RON required by the engine.
In Malaysia, Shell retails FuelSave (RON95), V-Power (RON97) and Diesel with Fuel Economy as its main products.
It also sells V-Power Racing, a top-end fuel, which it would only described as having a RON rating "above RON97". The product, available at only a few Shell stations in the Klang Valley and Johor, is touted as a premium fuel that offers more power and acceleration.
While Shell markets fuels by the same name in different countries, their octane rating varies from country to country.
A complex process
Fuel and vehicle engines are both complex systems. Understanding how fuel components work and interact with the engine and behave during the combustion process are keys to developing performance fuels.
The performance of a fuel depends on crude oil composition, available refinery streams, refining technology and performance components or additives.
With about 200 constituent parts in a petrol recipe, advancing motorsport fuel technology requires extensive research and development expertise.
While some elements are adapted for the extremes of motorsports, almost all component of a Formula1 fuel can be found in V-Power as well. Moreover, what Shell scientists learn when developing racing fuels is also transferred to the road with its V Power.
An additive called friction modification technology or “FMT”, found in V-Power 97 and V-Power Racing, acts as a lubricant clinging to the metal surfaces of the cylinder walls to reduce friction and allow the engine to turn more freely. This helps to provide better engine responsiveness.