RON 97 or RON 97? Yellow or green? Honestly, do you know the real difference or do you just know that for some reason RON 97 or the petrol with the green nozzle is the better one but it is more expensive so we don't use that one.
Well, since petrol is part of our daily lives and it helps us get from one place to another with our cars, don't you think it is important for us to know what we're putting into our cars?
Lucky for us, a Twitter user who also seemed clueless about petrol decided to compile a few questions from his followers and approached a local Engine Performance Analysis Engineer, Ir. Fadzil ZA who is now a lecturer with them and he gave us the answers we need!
Soal jawab berkenaan RON oleh pakar analisa enjin
— Aid Fawzal (@AidFawzal) May 31, 2022
Hampir setiap kali bila harga minyak naik, pasti soalan tentang RON akan timbul. Kali ni saya ubah konsep dengan bawakan anda tulisan daripada seorang Jurutera Analisa Prestasi Enjin yang kini menjadi pensyarah; Ir. Fadzil ZA. pic.twitter.com/eHOb3mwqaQ
So, let's get right into learning everything we should know about petrol!
+ What exactly is RON?
According to Ir. Fadzil ZA, RON is an abbreviation of Research Octane Number which is the measurement of the resistivity of gasoline to knocking. Knocking is an uncontrolled explosion that occurs in the combustion chamber. Knocking does not provide positive power but instead could cause an accident in the engine.
+ What's the difference between 95/97/100?
Ir. Fadzil ZA explains that actually, the calorific value for petrol with RON 95, RON 97 and RON 100 are more or less the same, with the only difference being the anti-knock quality.
So actually, there is no RON that is more powerful than the other because the energy content of all of them is the same. It is actually how the engine uses that excess fuel effectively that gives it extra power.
+ What is the relation between RON and the engine of a vehicle?
Ir. Fadzil ZA says that firstly, RON is directly proportional to the compression ratio rather than the size of your engine.
Thanks to technological advancement, car engines can change their tuning according to the RON used. Meaning that the RON value has less relation to vehicles compared to the past when it was very much related to the compression ratio of an engine. For example, a low compression ratio engine uses RON 95 while a high compression ratio engine uses RON 97.
One example that Ir. Fadzil ZA gave was the Mazda Skyactiv G which has a compression value as high as 14:1 and generally it should use RON 100 however, its new and advanced combustion chamber design allows it to use RON 95 without causing any issues.
+ Why are engines less sensitive to RON?
One of the main reasons is due to the advancement of the Engine Control Unit (ECU) available on the latest car models, says Ir. Fadzil ZA. Modern ECUs allow the engine to operate between different RON ranges; starting from RON 85 to RON 100.
Modern ECUs are able to adapt the value of fuel spray and ignition based on the quality of combustion to prevent knocking from occurring.
+ Types of engines best suited with high-value RONs
Petrol with a high RON is more suitable for use on engines that use forced induction such as Supercharger (SC) or Turbocharger (TC) says Ir. Fadzil ZA.
This is because engines that have SC/TC are more prone to knocking due to the incoming wind being pressurized and high temperature. So, high RON is more suitable because it can reduce or prevent the occurrence of knocking incidents that will degrade performance and also prevent damage to engine components.
+ Effects of using RON that is out of the allowed range
If an engine is tuned to use the range of RON 87 to RON 100 but is filled with RON 80, the car's ECU will only be able to use mapping for RON 87. The car's engine will most likely suffer severe knocking because the ECU can't control it properly says Ir. Fadzil ZA.
So, if the standard engine uses petrol such as RON 100 for racing. The ECU will only use the appropriate tuning for RON 100. So, you won't gain any advantage by using it.
+ Suitability to use RON 97/100 for low cc cars
If you can afford it, no problem says Ir. Fadzil ZA. However, the selection of the use of RON type is not based on the basis of engine size; cc. But it really depends on the design of the engine with the compression ratio track of a car. Like mention before, if you use a higher RON for lowe cc cars, you won't gain any advantage.
+ Which is more fuel saving? Low RON or high RON?
For this question, Ir. Fadzil ZA said you should refer to the unit of measurement. Most people make savings calculations only by guessing or seeing how far the distance travelled.
In a previous post by Dr Aid Fawzal, he shared how to compare the distance travelled with the price of petrol to find out sure if a car really saves petrol when using a different RON. Click here to read that post.
+ Conclusion
At the end of the day, you are advised to use a RON that is compatible with the specifications of your engine. This is because engines that are designed to use low RON, can work well when using high RON. While engines designed to use high RON, may not work well with low RON.
Now that was a pretty technical and detailed explanation, don't you think? Thank you Ir. Fadzil ZA and Dr Aid Fawzal!
What kind of petrol do you use for your car? Share your answer and what kind of car you use and why you choose that specific RON in the comments section. You might be able to help educate others on the subject!
