Malay Mail Online
December 2, 2014

PETALING JAYA, Dec 2 — With RON97 now only 20 sen more expensive than RON95, more Malaysians are now able to purchase it.

In 2012, both fuels used to have a price difference of RM1 per litre.

But what exactly is the difference between RON 95 and RON97 besides the price?

RON stands for Research Octane Number, a form of fuel quality and performance rating.

The rating system was developed by Russell Marker at American firm Ethyl Corporation in 1926, following Marker’s discovery that branching in hydrocarbons reduced “knocking”, or pre-ignition.

Following his discovery, oil refining companies rushed to increase the hydrocarbon branch chains to improve fuel quality.

A higher rating indicates the fuel can withstand higher levels of compression before detonating.

Higher compression levels may mean more power output.

Filling a vehicle with a lower octane rating than the one specified by the car manufacturer may lead to pre-ignition, a scenario that would ruin the car engine in the long-run or even result in an explosion.

Generally, higher octane fuels are used for vehicles with higher compression rations.

A higher compression ratio gives an engine a higher horsepower per engine weight than one with a lower compression ratio — making the engine “high performance”.

RON97 is recommended for drivers of vehicles with an engine capacity above 2,500cc.
Octane ratings offered to consumers vary from region to region.

Up until a few years ago, Australians were able to fill up with RON100 in major cities but can only choose from RON91, RON95 and RON98 fuels now.

In the United Kingdom, BP introduced BP Ultimate Unleaded 102, a petrol with an octane rating of 102 but stopped selling it in 2010.