Octane number higher than 87 "AKI" or 91 "RON"??
Han-Cheng Wu
The booklet of my car (1987 BMW 528e) says that I should use gasoline
with octane number higher than 87 "AKI" or 91 "RON". Is "AKI" the
standard used in United States? What do these two terms stand for?
What kind of gas should I use within United States? 87, 89, or 93?
(The compression ratio for the engine is 9.0). Thanks.
Kevin
S. M. Weems
the RON method is whats used in the US, and i believe stands for (R+O)/N.
unfortunately, i have no idea what the R, O, and N symbolize. i only know
this because gas pumps have that sticker that gives the octane rating, and then
say something like (R + O)/N method or words to that effect. I always thought
this was odd because every pump ive seen uses that method and i wondered
what other method is there? i guess AKI is it (:
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if you use the World Wide Web, please check out my home page listed below. (:
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S. M. Weems, Geology Major, University Of Alaska Fairbanks, Fairbanks, AK
fss...@camelot.acf-lab.alaska.edu http://camelot.acf-lab.alaska.edu/~fssmw3
"If you're not living on the edge, you're taking up too much space"
-----------------------------------------------------------------------------
Ed Hahn
On 3 Apr 1995, Han-Cheng Wu wrote:
> The booklet of my car (1987 BMW 528e) says that I should use gasoline
> with octane number higher than 87 "AKI" or 91 "RON". Is "AKI" the
> standard used in United States? What do these two terms stand for?
> What kind of gas should I use within United States? 87, 89, or 93?
> (The compression ratio for the engine is 9.0). Thanks.
the RON method is whats used in the US, and i believe stands for (R+O)/N.
unfortunately, i have no idea what the R, O, and N symbolize. i only know
this because gas pumps have that sticker that gives the octane rating, and then
say something like (R + O)/N method or words to that effect. I always thought
this was odd because every pump ive seen uses that method and i wondered
what other method is there? i guess AKI is it (:
====
Um, RON stands for Research Octane Number.
The sticker at the pump describes the "Pump" octane, which is (R+M)/2.
R = RON, M = Manufacturing Octane Number (or something like that).
To the original poster: you can use 87 octane at the Pump, which
should be equivalent to AKI. (I don't remember offhand what it stands
for, either :-). If you need to use higher grades, the owner's manual
should explicitly state that PREMIUM gas is required. (BTW, 9.0
compression ratio is average, these days.)
ed
-------- Ed Hahn | eh...@mitre.org | (703) 883-5988 --------
The above comment reflects the opinions of the author, and does not
constitute endorsement or implied warranty by the MITRE Corporation.
Really, I wouldn't kid you about a thing like this.
Ignasi Palou-Rivera
> Um, RON stands for Research Octane Number.
Right.
> The sticker at the pump describes the "Pump" octane, which is (R+M)/2.
> R = RON, M = Manufacturing Octane Number (or something like that).
MON = Motor Octane Number
Ignasi.
--
Ignasi Palou-Rivera Dept of Chem Eng, U Wisconsin
pa...@osnome.che.wisc.edu http://osnome.che.wisc.edu/~palou
|||| De Fraga a l'Alguer, de Salses a Guardamar.
Steven J. Reinhart
: the RON method is whats used in the US, and i believe stands for (R+O)/N.
: unfortunately, i have no idea what the R, O, and N symbolize. i only know
: this because gas pumps have that sticker that gives the octane rating, and then
: say something like (R + O)/N method or words to that effect. I always thought
: this was odd because every pump ive seen uses that method and i wondered
: what other method is there? i guess AKI is it (:
Isn't that (R + M) / 2 on the gas pumps?
-Steve
========================================================================
Steven J. Reinhart | rein...@netaxs.com
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* Finger rein...@netaxs.com for PGP Public Key *
========================================================================
Tom Coradeschi
>The booklet of my car (1987 BMW 528e) says that I should use gasoline
>with octane number higher than 87 "AKI" or 91 "RON". Is "AKI" the
>standard used in United States? What do these two terms stand for?
>What kind of gas should I use within United States? 87, 89, or 93?
>(The compression ratio for the engine is 9.0). Thanks.
You can probably use 87 octane just fine. If the engine pings or knocks,
bump up to 89, but don't do it if you don't have to (it's just wasted
money).
AKI stands for Anti Knock Index, and is what we commonly refer to as
"Octane." Hence my recommendation for use of 87 octane gas.
RON stands for Research Octane Number. This is, I believe, what you'll
find on the pump in Europe.
In the US, the AKI is actually the average of the RON and the Motor Octane
Number (MON). On the pump, you'll typically see something like "(R+M)/2"
indicating this.
tom coradeschi <+> tc...@pica.army.mil
http://k-whiner.pica.army.mil/
Mark Olson
[ snip ]
: ====
: Um, RON stands for Research Octane Number.
: The sticker at the pump describes the "Pump" octane, which is (R+M)/2.
: R = RON, M = Manufacturing Octane Number (or something like that).
I believe the "M" stands for "Motor".
Cheers,
Mark
--
Mark Olson Sr. Test Engineer * e-mail - ols...@adc.com
ADC Telecommunications * voice - (612) 936-8008
4900 West 78th Street, MS 107 * fax - (612) 936-8277
Minneapolis MN 55435
Michael J. Wrublewski
"S. M. Weems" <fss...@camelot.acf-lab.alaska.edu> wrote:
>On 3 Apr 1995, Han-Cheng Wu wrote:
>> The booklet of my car (1987 BMW 528e) says that I should use gasoline
>> with octane number higher than 87 "AKI" or 91 "RON".
>the RON method is whats used in the US, and i believe stands for (R+O)/N.
>unfortunately, i have no idea what the R, O, and N symbolize.
Close, but no cigar!
RON stands for Research Octane Number, and it isn't what is shown on the
pump. The pump formula is (R+M)/2. The "R" stands for the RON value the
"M" stands for another value which I can't seem to find. :-(
It is the average of these two values that is found on the pump.
Rule of Thumb: 91 RON = 87 Pump
98 RON = 93 Pump
=========================================================================
Michael J. Wrublewski | "You can't achieve the
Core & Advanced Powertrain Engineering | impossible, without
(mwru...@pt0102.pto.ford.com) | attempting the absurd."
=========================================================================
My views do not reflect those of the Ford Motor Company
Martin O'Toole
(Michael J. Wrublewski) writes:
>
>In article <Pine.NXT.3.91.950403020457.306G-100000@guinevere>,
> "S. M. Weems" <fss...@camelot.acf-lab.alaska.edu> wrote:
>>On 3 Apr 1995, Han-Cheng Wu wrote:
>>> The booklet of my car (1987 BMW 528e) says that I should use
gasoline
>>> with octane number higher than 87 "AKI" or 91 "RON".
>
>>the RON method is whats used in the US, and i believe stands for
(R+O)/N.
>>unfortunately, i have no idea what the R, O, and N symbolize.
>
>Close, but no cigar!
>
>RON stands for Research Octane Number, and it isn't what is shown on
the
>pump. The pump formula is (R+M)/2. The "R" stands for the RON value
the
>"M" stands for another value which I can't seem to find. :-(
>
>It is the average of these two values that is found on the pump.
>
>Rule of Thumb: 91 RON = 87 Pump
> 98 RON = 93 Pump
Correct! "M" stands for motor octane, a number arrived at through a
different test method than research's method. "Motor" gives a # in the
low 80s. R+M /2 gives AKI, the # on the pump.
Matt>
>=======================================================================
Tony Tsakiris
: On 3 Apr 1995, Han-Cheng Wu wrote:
: the RON method is whats used in the US, and i believe stands for (R+O)/N.
RON stands for 'research octane number.' MON stands for 'motor octane number.
RON and MON are two test methods for rating a fuel's anti-knock quality.
'Octane number' as reported at many gas pumps is an average of the two results,
(RON +MON)/2.
----
Opinions expressed are my own, not necessarily those of my employer.
\\\Slant-6 Daniel///
AKI, Anti Knock Index, is derived by taking the average of the RON
(Research Octane Number) and the MON (Motor Octane Number.) That is why
the yellow stickers on the gas pumps say "R+M/2"
SL6 Daniel
On Wed, 5 Apr 1995, Dr. B. R. Gopal wrote:
> WRONG!!! AKI and RON are just two standard units to indicate the
> anti-knock properties of a fuel. AKI stands for 'Anti Knock Index'
> and RON stands for 'Research Octane Number'. 87 AKI is more or less
> equivalent to 91 RON. I could possibly dig out more info if you care
> to e-mail me.
> Ravi
>
>
>
Dr. B. R. Gopal
> > standard used in United States? What do these two terms stand for?
> > What kind of gas should I use within United States? 87, 89, or 93?
> > (The compression ratio for the engine is 9.0). Thanks.
>
> this because gas pumps have that sticker that gives the octane rating, and then
> say something like (R + O)/N method or words to that effect. I always thought
> this was odd because every pump ive seen uses that method and i wondered
> what other method is there? i guess AKI is it (:
>
WRONG!!! AKI and RON are just two standard units to indicate the
Ignasi Palou-Rivera
> Resarch Octane is the anti-knock ability of gas as meausured by chemical
> analisys. Motor Octane is the anti-knock ability of gas as meausured in a
> test engine. The two values are avaraged '(R+M)/2' to get the pump octane
> value you see on the yellow sticker.
Not exact. Both the RON and the MON are determined using test
engines. The difference being the test conditions. One of them (I
always forget which one) is run under more severe conditions (sudden
accelerations, load changes,...) while the other one is much
easier.
Both the RON and the MON can be predicted (although to a degree) by a
chemical analysis of the gas in most ordinary conditions. That is if
there are no 'weird' substances in there.
Bob Goudreau
>
> On 3 Apr 1995, Han-Cheng Wu wrote:
> > The booklet of my car (1987 BMW 528e) says that I should use gasoline
> > with octane number higher than 87 "AKI" or 91 "RON". Is "AKI" the
> > standard used in United States? What do these two terms stand for?
> > What kind of gas should I use within United States? 87, 89, or 93?
> > (The compression ratio for the engine is 9.0). Thanks.
>
> the RON method is whats used in the US, and i believe stands for
> (R+O)/N. unfortunately, i have no idea what the R, O, and N
> symbolize. i only know this because gas pumps have that sticker that
> gives the octane rating, and then say something like (R + O)/N method
> or words to that effect. I always thought this was odd because every
> pump ive seen uses that method and i wondered what other method is
> there? i guess AKI is it (:
I don't know what AKI is, but you're very confused about RON and US
octane ratings.
There are two standard ways to measure octane: RON, which stands
for "Research Octane Number" and MON which stands for "M<somthing>
Octane Number" (I forget what the M stands for -- "Motor" or
"Measured", perhaps?) RON is usually higher than MON by 8-10 points.
In many countries (e.g., European ones), the octane rating listed
on a pump is the fuel's RON. In the United States, a different
method, called "(R+M)/2" is used. Not surprisingly, that method is
to just take the average of the fuel's RON and MON. One result is
that pump octane ratings appear much lower in the US than they do in
Europe, even when the real octane levels are identical or higher.
For example, a fuel whose RON=98 and whose MON=88 would be sold as
"98 octane" fuel in, say, Greece; in the US, it would be sold as
"93 octane", because (98+88)/2 = 93.
In the case of your BMW, you should be safe with any regular
unleaded gasoline, since even 87 octane fuel should have a RON
>= 91. Perhaps "AKI" stands for "Average K<something> Index",
and is just really a synonym for the (R+M)/2 method.
----------------------------------------------------------------------
Bob Goudreau Data General Corporation
goud...@dg-rtp.dg.com 62 Alexander Drive
+1 919 248 6231 Research Triangle Park, NC 27709, USA
Andrew P. Bajorinas
]
]
]Correct! "M" stands for motor octane, a number arrived at through a
]different test method than research's method. "Motor" gives a # in the
]low 80s. R+M /2 gives AKI, the # on the pump.
]
The octane number "M" is from a knock engine. It is basically a test engine with
precise specifications. The engine is run at a given speed, temperature, etc... and
the timing is advanced until it knocks. This point gives the motor octane. The "R" octane
number is a little more complicated.
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| Andrew P. Bajorinas Bajo...@Perkin-Elmer.com |
| -----------------------------------------------------------------------|
| The above opinions are my own. | I will never let my cat |
| My employer thinks I am working. 8^) | use my net access again! |
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