RON95 vs RON97, My Experience

 We have seen numbers like RON95 and RON97 in petrol stations. At the time of writing, fuel with a RON97 rating is priced more expensive at RM2.05 per liter while RON95 is going for RM1.80. I do not blame the govt for higher fuel prices in future. If we want to grow into a developed country things have to get more expensive, common economic sense. Ubahla gaya hidup a.k.a Change your lifestyle. The question is which is better? Why is RON97 more expensive than RON95? What is the difference? Should I opt for the cheaper fuel? Let's tackle these questions one by one.


What is this RON rating?
It stands for Research Octane Number, a rating or measure of the knocking resistance of petrol in spark-ignition internal combustion engines. Mumbo-jumbo explanation? Well, knocking refers to parts or all of the air-fuel mixture prematurely ignites before the flame from the spark plug can reach it. Thus causes a decrease in performance and could to a certain extent damage the pistons of the engine.

Lower octane can handle less amount of compression before igniting. Imagine being compressed halfway and the fuel kabooms which implies that knocking can happen easier when using lower octane fuel such as RON95.


Why is RON97 more expensive than RON95?
With a fuel that is able to handle higher compression before ignition certainly means a better fuel quality. Therefore it is fair to say that quality commands a better price. As simple as that.


So which is better?
Basically the compression ratio of your engine determines the octane rating of the gas you must use in the car. It is a big misunderstanding to think that RON97 fuel produces more power than RON95 but in reality higher rating means less fuel burns less easily (reduction in premature ignition). Engines are designed to have a minimum RON rating for its fuel. There are three official ways to check:

1. Check your service manual or booklet for the minimum RON rating that it requires. 
2. Check if there is a min octane number rating at the back of the fuel lid cover.
3. Ask the car manufacturer or the salesman. If he/she can't answer better not buy the car from that sohai person.
4. Or, refer to the reference table below (not a complete list though). The effects of using lower RON then the min requirement means knocking will happen!

 

Note: The reference table is just for guide purposes only, for confirmation please contact your nearest car manufacture service center. 

BUT...hear aboi out first :)
I have tested both RON95 (Shell Fuel-Save) and RON97 (Shell V-Power) on my Myvi (AT) 1300 cc. Before showing the results, it is good to know what are the variables I am trying to fixed during my trial run.

• No additional weight in my car (no extra things/burdens in my boot)
• Average driving speeds of 60kmph-80kmph. I follow speed limits after some hard learnt lessons.
• I do not rev or "lap" above 2500 revolutions per minute. No more ah beng style.
• I always inflate my tires to optimum pressure each time I refill my tank.
• 90% of my driving mileage is from home to office and vice versa.

With RM50 I will get 27.78liters of RON95 and 24.39liters of RON97. The results are 350km for RON95 and 310km for RON97. It was higher last time because my tires are quite worn out after 3 years (I will change soon). This translates into:

• RON95: 12.60km/liter
• RON97: 12.70km/liter (RON97 fuel is marginally better!, I guess also more green as I use less fuel)

The performance of RON97 is the thing that made me go WOW! in comparison to RON95 where I feel there is not much pick up & makes my car feel underpowered. RON97 indirectly delivered more power from less knocking. I can testify that using RON97 will make your driving more pleasurable & enjoyable.


Should I opt for cheaper fuel?
My answer is NO, I will be using RON97 now onwards. Results have shown that using RON97 has comparable mileage to RON95 while using less fuel at the same time, this only means I have avoided a chunk of knocking happening inside the engine. I am a believer of quality and I am planning to keep my car until it is at least 10 years old so I have to preserve the engine for as long as possible. This is unless I can justify my earnings vs spending (because car is a liability not an asset).

My monthly fuel spending equates to RM200, I drive almost 1400km each month. A 160km setback while on RON97 means an additional RM26 on top of RM200. I could offset by changing my driving style as I start to get familiar with RON97 or I just pump it. If the latter, RM26*7years*12months = ~RM2200. That is still hell a lot cheaper than buying a damn new car!

I would conclude that RON95 is applicable in highways or cruising mode but RON97 is more suited for city driving where performance matters at low gears because we tend to stop a lot more often. Try it, experiment with it, I highly recommend RON97.