Know Your RON

03 August 2009

Do you know your RON or Research Octane Number? With the new petrol grade RON95 to be launched officially on 1 September 2009, allow us to give you a heads up.

While RON has been around for a long time, especially in the form of RON92 and RON97, most motorists don't pay much attention to it. Octane numbers refers to the ability of the fuel to resist self-igniting in the combustion chamber before the spark plug fires. If that happens, the engine will experience "knocking" and become rough; this could possibly damage the engine over time.

Petrol that has a higher RON rating (or number) will have a stronger resistance to causing knocking compared with petrol with a lower RON rating.

But do all engines need to use the fuel with the highest RON rating? The answer is no.

All engines are designed to run on the minimum RON rating petrol recommended by their manufacturers. If your manufacturer specifies that the minimum requirement is RON95, using RON97 will not harm the engine. But you might end up paying more without getting any gain in performance. However, using fuel with a lower-than-recommended RON rating can cause engine damage.

Come 1 September, RON92, now priced at RM1.70 per litre, will be phased out and replaced by RON95, which will cost 5 sen more.

The other grade, RON97, will continue to be sold but its price will be increased by 20 sen per litre to RM2.

To know your car's RON rating, just look up the owner's manual or at the inside of the fuel lid of your car's fuel tank. Modern engines with knock sensors could run on fuel with a low RON rating, as the engines can adjust their spark timing automatically to eliminate the knocking. However, the car's fuel consumption, drivability, and power may be affected. Using the right RON rating fuel based on the engine's design and tuning will maximize vehicle performance.

About 84% of petrol sales in Europe are that of RON95 and 85% of sales in Japan are RON89 and RON90. With the majority of cars in Malaysia are using engine technologies from Europe and Japan, the introduction of RON95 should not pose problems for local motorists.

Proton, whose cars easily form the bulk of the passenger cars on local roads, says that all its models, whether fitted with carburetor or the latest Campro CPS engines can run on RON95. However, the Malaysian car maker did indicate that some of its earlier carburetor-equipped models, depending on the condition of the engines, might experience some knocking. Owners can solve the problem by getting the ignition timing of their cars adjusted at Proton- authorised service centres.

Perodua cars are even better off, with most models already tuned to run on RON90, meaning that owners can save 10 sen by using RON92 instead of the more expensive RON97. Again, if in any doubt, refer to the car's manual.

Even imported cars like Toyota and Kia are ready to run on RON95.

You do not have to wait until your tanks are near empty before filling up with RON95 petrol. Fuels of different RON ratings can be mixed safely without causing any harm to the engine. Many owners whose vehicles could operate on RON95 or below were using the more expensive RON97.

The higher RON number does not mean that the fuel is more powerful. Vehicles that require a higher octane fuel are usually sports cars or those with turbocharged engines. In any case, RON97 will still be in the market if your vehicle really needs fuel of that grade to perform at peak performance.

Excerpt from The Star

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