ni ada korek dari net sket..
With the recent Government's intention to hike petrol prices based on RON ratings, with RON95 at RM 1.75 and RON97 at RM 2.00, what exactly is RON ratings anyway? Well... this article is dedicated to satisfy your curiousity and quench your thirst for knowledge toward this RON thingy..
So what is RON? He's definitely not your next-door neighbour. What does the RON number mean in regard to petrol?
Unleaded fuels carry a RON (Research Octane Number) rating. Put simply, RON determines petrol’s ‘anti-knock’ quality or resistance to pre-ignition; or if you want to put in another way, the Octane Number denotes its resistance to detonation.
If you run your vehicle on low octane petrol you might notice a ‘knocking’, ‘rattling’, or ‘pinging’ sound (as it’s often called), which means the fuel is detonating instead of burning smoothly. This is not only a waste of energy, but it can also damage your engine in the long run. Burning is the desired effect of any internal combustion engine (not an explosion per se).
Fuel with a higher octane number suitable for your vehicle’s engine will eliminate knocking. Older cars that were designed to run on a lower RON fuel can also benefit from a higher RON, because the older the car and the higher the kilometres, means the engine will have a greater propensity to knock. This is mainly caused by a build-up of contaminants and carbon deposits which, when hot, can cause pre-ignition.
Rotary engines suffered from this too. As carbon deposits build up on the three apex seals of each rotor, the deposits get so hot, they glow orange with heat and then bang…detonation!
If you’ve ever seen an apex seal with what looks like burnt, corroded and ‘blown’ corners, you’ll know why. So in effect, a higher RON fuel when used in these situations will have a much higher threshold to detonate, therefore reducing that nasty characteristic of detonation.
98 RON is promoted as providing excellent fuel economy. It has low levels of benzene, sulphur and lower aromatics: its sulphur content is 10 times lower than the national standard for unleaded fuels.
For performance cars, 98 RON go-go juice is the norm. But does a car that is designed to run on 95 RON fuel run better on 98 RON fuel? Some swear by it, but from what I have seen, I have no evidence to sustain that theory. Sure, you may get better mileage, but I am skeptical that we would see measurably positive results on the dyno. However, there are certainly exceptions to any rule, and there are just so many variables to consider it’s not worth turning the discussion into argument.
The basic principles of internal combustion technology in cars has changed little; where things have changed however is in programming and in the sophisticated fuel management systems (such as knock sensors) of modern cars.
Some engines are fitted with a device called a knock sensor. Regardless of whether your vehicle has a knock sensor or multiple knock sensors, if it has high mileage, a higher RON fuel would be the most mechanically sympathetic thing to do. Why is that?
You see the knock sensors in your engine (if equipped) have a job to do. They protect your engine from knock by retarding timing; but here is the thing - your car ‘has’ to knock first before the knock sensors can do their job! This is not a good start in the first place. When an engine ‘knocks’ the engine temperature soars, and with most modern engines using an all alloy block, heat is bad… very bad.
Older engine blocks were commonly made from iron, and iron has a much higher melting temperature (at around 1,500 degrees centigrade) whereas an alloy block (we’re generalising here) melts at around half that temperature (being approximately 800 degrees centigrade).
Having first-hand experience with race engines that run an engine management system like a MOTEC tuned for a race fuel like ELF W.L.F (World Rally Fuel) at 102 RON ( the FIA limits for racing fuel is 102 octane), I’ve seen an engine ‘melt’ internally after just getting a ‘whiff’ of 98 RON when the engine was tuned for 102. Temps went through the roof and the engine was a throw-away proposition. This gets pretty expensive, let me tell you.
Of course this doesn’t happen anywhere near as dramatically with passenger cars built for consumer use, and most race engines don’t employ knock sensors to retard timing. It does however illustrate - at the higher end of the spectrum - just how important running the right RON for an engine can be and just how serious knock is.
So what does all this RON nonsense mean to the average motorist? Does it give you more power like many people suggest? Can you really ‘feel’ that extra power via the driver’s seat? Does a higher RON fuel equal better fuel consumption? The answer to these questions is somewhere between “maybe” and “yes”, but it depends a lot on your car, its state of tune, and how you drive.
So what do you next time you find yourself at the petrol pump?
My advice is reach for the better stuff. Not only are you “spreading the love” to your engine, but you will likely see better mileage and you will be doing your bit for the environment. On the whole, the higher the RON, the cleaner the emissions.
Till next time, Happy and safe motoring.
p/s: tapi awat rasa mcm x smooth ha? hahah