Hmmm.. Then I will try Esso and Shell to see which one give me a better $$ economy. Thanks for the heads up.
Does RON number impact fuel efficiency?
- Thread starter lsisaxon
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Hmmm.. Then I will try Esso and Shell to see which one give me a better $$ economy. Thanks for the heads up.
I thinkn can pump hydrogen in.. but water......... hmmm.... Cold fusion engine? ;p Or like Back To The Future, the car which runs on trash? ;p
to straighten things up abit here.
The correct terms to use for knocking is uncontrolled detonation. Commonly termed as knocking or pinging. During a uncontrolled detonation in 4 stroke cycle, the fuel self-combust (ie detonated) during the compression cycle before the sparking of the plug. This uncontrolled detonation created tremendous amount of pressure within the cylinder and creates shock wave which will resonate and becomes a knocking sound.
The detonation is a result of compression rather than the commonly believe hot piston.
In a 4 cylinder car, such detonation occurs during compression cycle, the piston is moving upwards and compressing but the detonation has already occurred so it is fighting the compression action of the piston. The stress here is tremendous.
In order to curb this uncontrolled detonation, tetra-ethyl lead was used. The RON rating, as many has pointed out, is the ability of the fuel to withstand compression.
Modern car engines are equipped with knock sensors and will automatically retard engine timing to prevent engine 'knocking'. However, the retard in timing is at the expense of peak efficiency for the engine. Therefore, RON does affect engine power output especially under load (ie uphill).
As for fuel economy, the lower RON will only improve carburettor engine. For modern fuel injected engine, the ECU is able to run at optimum air to fuel ratio via the O2 sensors.
So why still pump lower RON petrol? Because the difference in power output for RON 98 and RON 95 and RON 92 is negligible for family sedan cars but the price difference is HUGE! And thus the savings in $$$.
As for blowing engine on performance cars using low RON petrol, is because the ECU can only retard the engine timing to a certain level, especially so for forced inducted engines whereby the air is much hotter and in much higher pressure when entering the cylinder.
The correct terms to use for knocking is uncontrolled detonation. Commonly termed as knocking or pinging. During a uncontrolled detonation in 4 stroke cycle, the fuel self-combust (ie detonated) during the compression cycle before the sparking of the plug. This uncontrolled detonation created tremendous amount of pressure within the cylinder and creates shock wave which will resonate and becomes a knocking sound.
The detonation is a result of compression rather than the commonly believe hot piston.
In a 4 cylinder car, such detonation occurs during compression cycle, the piston is moving upwards and compressing but the detonation has already occurred so it is fighting the compression action of the piston. The stress here is tremendous.
In order to curb this uncontrolled detonation, tetra-ethyl lead was used. The RON rating, as many has pointed out, is the ability of the fuel to withstand compression.
Modern car engines are equipped with knock sensors and will automatically retard engine timing to prevent engine 'knocking'. However, the retard in timing is at the expense of peak efficiency for the engine. Therefore, RON does affect engine power output especially under load (ie uphill).
As for fuel economy, the lower RON will only improve carburettor engine. For modern fuel injected engine, the ECU is able to run at optimum air to fuel ratio via the O2 sensors.
So why still pump lower RON petrol? Because the difference in power output for RON 98 and RON 95 and RON 92 is negligible for family sedan cars but the price difference is HUGE! And thus the savings in $$$.
As for blowing engine on performance cars using low RON petrol, is because the ECU can only retard the engine timing to a certain level, especially so for forced inducted engines whereby the air is much hotter and in much higher pressure when entering the cylinder.
Thanks for the explanation! :thumbsup: So RON does impact efficiency... Which means there should be an optimum RON for each car, right?
I just pumped my 3rd 3/4 tank of RON92 petrol today and it does seem like my FC is taking a slow plunge from 14km/l down to 13km/l. I think I will go back to RON95 for my next few top up to see if I can get back 14km/l. That does translate into $0.14/km(RON95) vs $0.15/km(RON92).... I need more statistics but I'm impatient.. ;p
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