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ok i was at the gas station today and noticed the choices are 87, 89, and 91 MOR (Minimum octane rating)...i've done some lazy searching on here but would like some more input on these read outs. i noticed in my manual it says 86 or HIGHER PON (pump octane number) and under the tail is says 91 or higher RON (??? don't know what this stands for?)....anyone have the link for the different readings. i did see on a thread that it does say at the pump they use PON to measure octane BUT here in the bay area (california) i noticed at the pump it says 89 MOR or 91 MOR not PON? can anyone clarify for me please? thanks! BTW...i did convert to 89 from 91 =) haha
 

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The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel through a specific test engine with a variable compression ratio under controlled conditions, and comparing these results with those for mixtures of isooctane and n-heptane.

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. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a 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. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-95 (regular) in Europe.

The octane rating may also be a "trade name", with the actual figure being higher than the nominal rating.

It is possible for a fuel to have a RON greater than 100, because isooctane is not the most knock-resistant substance available. Racing fuels, straight ethanol, Avgas and liquified petroleum gas (LPG) typically have octane ratings of 110 or significantly higher - ethanol's RON is 129 (MON 102, AKI 116). Typical "octane booster" additives include tetra-ethyl lead and toluene. Tetra-ethyl lead is easily decomposed to its component radicals, which react with the radicals from the fuel and oxygen that would start the combustion, thereby delaying ignition.
 
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Just so i am straight:

AKI, (R+M)/2, RdON, and PON are all the same thing in the United States?
 

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I am confused! =-/ I put in the best that they have at the pump. My baby only takes a few gal. to fill, why be a cheap ass?! I'm use to the prices, I've always had to use premium fuel in my modded Audi A4. I have custom mapping that requires high octane.
 

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TippinRR said:
James, you might have just sparked the debate.. do your research and come back..

Why should I research? I have to use 91 in my car because my Eprom requires that octane and the manufacturer suggests it for advanced timing. If you use lower in my car it pings. The software designer of my chip states specifically to use 91 or higher at the pump. Higher octane fuel has only one beneficial feature - it allows an engine to run at higher temperatures with more advanced ignition timing under higher levels of compression witout detonating / knocking. Also, I found that in my cars over the past 20 years lower octane gas causes a build up of crud around the injectors. Although I hear that the newer gas today, in lower octanes, no longer causes that crud. I use 91 in the 600RR because that is what I have always put in my bikes, but this is the first newer generation bike I have owned. I do know that 91 seems to run good in my bike, no problems that I have noticed. It also is a good idea to use a gas with an addative, like Chevron w/Techron. I have read and heard from people who say that a low octane fuel causes their RR to ping or knock. I also get excelent mileage using 91, but I'm not saying I wouldn't with 87...I don't know.
 

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yes, yes we know that, he is saying not to start another thread about octane levels and which one to use... there are enough of them on this site already. If your RR is stock, no need to use anything but the cheap stuff... if you have pinging from cheap stuff it is either bad gas, or you have aftermarket mods to your bike that require you bump up to a higher octane. The bike is designed to run on 86, where as your A4 was modded, and therefore "designed" to use higher octane.

Please everyone, lets stay on topic here, the title of the thread is "question about OCTANE rating here in cali...not a debate thread! lol "

don't offer opinions/facts about which octane rating to use, the thread is about the differences in rating methods.
 

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slab42 said:
yes, yes we know that, he is saying not to start another thread about octane levels and which one to use... there are enough of them on this site already. If your RR is stock, no need to use anything but the cheap stuff... if you have pinging from cheap stuff it is either bad gas, or you have aftermarket mods to your bike that require you bump up to a higher octane. The bike is designed to run on 86, where as your A4 was modded, and therefore "designed" to use higher octane.

Please everyone, lets stay on topic here, the title of the thread is "question about OCTANE rating here in cali...not a debate thread! lol "

don't offer opinions/facts about which octane rating to use, the thread is about the differences in rating methods.
Okay, but it seems the people having a problem in this thread are those that are NOT from California. It seems you have no business being in this thread anyway, it is for those in California only. =-)
 

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If you are going to use low grade, buy "good gas". Meaning, at least get it at Chevron, Mobil, Shell, etc. NEVER use Thrifty gas or the like. It does show on a sticker under the pass seat that we have a MIN 91 RON sticker. That is we are to use 87 at minumum but certainly can use higher grade if we so choose. Remember friends from outside California, we have crappy gas here that is oxygenated and extra refined due to our California clean air act. We are known for crappy gas, so I choose to put in the best of the crap. =-)
 

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i run premium but regular unleaded is fine for you
 

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Ocho Cinco
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91 OCTANE is what I always put in my bike. Manual states anything 86 and higher...
 

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Under the passenger seat on the info sticker it says 91. I use 91 it is only 5-6 bucks to fill it up.
 

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madbrown75 said:
It is possible for a fuel to have a RON greater than 100, because isooctane is not the most knock-resistant substance available.
pure isooctane is 100 RON, fyi. just thought i'd throw that in there =)
 
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