Higher octane
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Joined: Aug 2002
Posts: 44
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From: Maryville, TN
Vehicle: 2000 Accent
Higher octane
When you turbo your car, people get it tuned for 93 octane gas. Do you have to use 93 when using nitrous or can you still use 87 without detonation while spraying?
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Joined: Aug 2010
Posts: 163
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From: Lowestoft-England
Vehicle: F2 Evolution
87 and 93? No wonder your fuels so cheap, it's watered down!
In the Uk we have 95 and the "supers", these vary, most are 97, Shell is 98, and theres also Tesco (supermarket chain) which is 99-though also 15% ethanol and has no additives that branded fuels have, such as injector cleaner.
At Silverstone I've also seen 102 on pump.
Biggest problem for me is my other car, a 1999 Accord type R 2.2 is mapped to take 98 ron and above- means I have to use Shell, and most Shell stations in my area have gone! have to drive 10 miles out of my way for fuel.
In the Uk we have 95 and the "supers", these vary, most are 97, Shell is 98, and theres also Tesco (supermarket chain) which is 99-though also 15% ethanol and has no additives that branded fuels have, such as injector cleaner.
At Silverstone I've also seen 102 on pump.
Biggest problem for me is my other car, a 1999 Accord type R 2.2 is mapped to take 98 ron and above- means I have to use Shell, and most Shell stations in my area have gone! have to drive 10 miles out of my way for fuel.
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Joined: Mar 2006
Posts: 9,533
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From: tacos
Vehicle: 2000 Elantra
Research Octane Number (RON)
The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane.
Motor Octane Number (MON)
There is another type of octane rating, called Motor Octane Number (MON), or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load, as it is determined at 900 rpm engine speed, instead of the 600 rpm for RON.[1] MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON, however there is no direct link between RON and MON. Normally, fuel specifications require both a minimum RON and a minimum MON.[citation needed]
Anti-Knock Index (AKI)
In most countries, including Australia and all of those in Europe, the "headline" octane rating shown on the pump is the RON, but in Canada, the United States and some other countries, like Brazil, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI, and often written on pumps as (R+M)/2). It may also sometimes be called the Pump Octane Number (PON).
The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane.
Motor Octane Number (MON)
There is another type of octane rating, called Motor Octane Number (MON), or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load, as it is determined at 900 rpm engine speed, instead of the 600 rpm for RON.[1] MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON, however there is no direct link between RON and MON. Normally, fuel specifications require both a minimum RON and a minimum MON.[citation needed]
Anti-Knock Index (AKI)
In most countries, including Australia and all of those in Europe, the "headline" octane rating shown on the pump is the RON, but in Canada, the United States and some other countries, like Brazil, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI, and often written on pumps as (R+M)/2). It may also sometimes be called the Pump Octane Number (PON).