What most of us know about RON 95 and RON 97 is that RON 97 is more expensive than RON 95. Since the recent reduction in the price of RON 97 on 1st of December 2014, the price difference between RON 97 and RON 95 is quite low – about 20 cents difference. But still RM1 every 5 liters can add up at the end of the day. The price reduction of RON 97 has increased the demand for RON 97 and more and more people have been using it, but does it really do anything for engine performance? Maybe you’ve had some ‘mamak’ conversations about RON 95 and RON 97 – about whether it actually increases engine performance and whether it’s worth the price to pay more for. But before we start the factual comparisons of RON 95 and RON 97, let’s firstly be clear about RON – what is it and what does it stand for? RON is an abbreviation for Research Octane Number and is basically a measure of the quality and performance of the fuel. RON is calculated by measuring a fuel’s knocking resistance in spark-ignition internal combustion engines. Knocking is what happens before the flame from the spark plug reaches the air-fuel mixture and ignites prematurely. Premature ignition can cause a decrease in performance and might also harm the engine.The higher the RON, the better the fuel’s knocking resistance and the fuel’s ability to delay auto ignition.
So which fuel should you use – RON 95 or RON 97. First of all, you should consider the vehicle you are driving. Check your vehicle’s service manual for the minimum RON rating that it requires. If your engine requires a minimum of RON 95, you might as well use RON 95 as it is cheaper than RON 97. Using RON 97 on a vehicle that only requires RON 95 is a waste of money as it hardly increases engine performance.However, if your engine requires a minimum of RON 97, then be ready to pay a little more for fuel because filling your engine with a lower RON than the one specified might lead to premature ignition which can damage your engine in the long-run and in the worst case scenario, result in an explosion. Generally, cars with higher performance engines or engine capacity above 2400cc use RON 97. Most cars in Malaysia are built to run on RON 95. Some newer high compression engines also run on RON 95.
Contrary to popular belief, RON 97 does not make your engine perform better; rather it actually makes fuel burn less easily. RON simply refers to the ability of the fuel to resist knocking and delay auto ignition. Some may argue that the engine oil in vehicles using RON 97 stays cleaner longer as a result of the combustion generating lower heat. But actually RON 97 stays cleaner longer because of the detergents used and has nothing to do with the combustion rating.
Another common misperception about RON 97 is that it gives you more mileage than RON 95. In fact, the amount of mileage you get has to do more with how you handle your vehicle and the traffic conditions.
Here is a comparison of the RON 97 and RON 95 prices from late 2013 to late 2014.
| Date | Price of RON 97 per liter | Price of RON 95 perliter |
| September 2013 | RM2.85 | RM2.10 |
| January 2014 | RM2.80 | RM2.10 |
| March 2014 | RM2.90 | RM2.10 |
| October 2014 | RM2.75 | RM2.30 |
| November 2014 | RM2.55 | RM2.30 |
| December 2014 | RM2.46 | RM2.26 |
In conclusion, a higher price doesn’t always mean better quality per se. In this case, it very much depends on the requirements of your vehicle. The rest is just marketing. Now tap yourself on the back for reading this article and minding your wallet, it takes effort, but ignorance is not bliss