MINI2

duncs · Sep 3rd, 2003, 09:44 AM

This has probably been covered in some thread somewhere, although I couldn't find it.
I have seen a lot of references around as to how good Shell Optimax is.
I thought this was 98 Octane fuel, and from memory I thought that JCW tell you to use 95 to 97 Octane.
I use Super Unleaded ( 97 Octane ) at the moment, can I use the Optimax or is it to higher Octane level.
Or have I misread or misunderstood something?

If I can use it, any comments / reports on the differences to super?.

Tall bloke · Sep 3rd, 2003, 09:56 AM

I only ever use Optimax in my works s. Can't really give you a comparison, because i have never filled up with anything else (even before the conversion).

Chris

duncs · Sep 3rd, 2003, 10:04 AM

I assume, having never used anything else that you have had no problems?.
Provided I can't find any negative comments, I will give it a go.
As opposed to you I have never used it.

Tall bloke · Sep 3rd, 2003, 10:07 AM

I have put 18000 miles on my car in a year, and can count on one hand the amount of times i have used petrol other than Optimax. I have had no problems what so ever.

Cheers
Chris

duncs · Sep 3rd, 2003, 10:32 AM

Thanks Mate
Will give it a go.

davidac · Sep 3rd, 2003, 12:27 PM

I know the numbers don't convert directlyto US, or at least I think I know. What is the conversion approximately. 98 octane in the UK is equivelant to what in the US? The hightest octane widely available is anywhere from 92-94 depending ont he station here, but I think those numbers are calculated differently. I am sure someone knows, care to explain?

duncs · Sep 3rd, 2003, 03:19 PM

As far as I was aware, the octane rating was a standard number wherever you were.
I thought basically, the higher the octane rating the less likely the fuel was to pre-ignite ( due to compression and not the spark ), i.e. reducing effiency.

I know that in high altitude countries you tend to get lower octane rating fuel, I guess this is something to do with available oxygen.

I know that in south africa around in Gauteng ( approx 2000m above sea level ) that most Garages supply 93 or 95 octane fuel.
If I remember in Cape Town ( sea level ) you can get 97 octane.

Here in the UK, it ranges from 93 to 97 ( typically ) Optimax is 98.

I know this probably doesn't answer your question, I'm hoping there is a budding Chemist out there who may be able to tell me I am talking rubbish and explain the process properly.

d2create · Sep 3rd, 2003, 10:23 PM

In the US, most gas stations offer three grades. 87, 89, and 93. In California i believe it's very hard to find anything over 91 due to stricter emissions.
So for the US, what octane does the S call for?

Critical · Sep 3rd, 2003, 10:40 PM

Ok, the octane ratings in europe and the US are the same. They are the ability of the fuel to withstand compression-induced ignitions. The higher the octane rating, the more it can be compressed before it will ignite. High performance engines require higher octane fuels because they compress the fuel more before they ignite it (spark). If you put low octane gas in a high compression engine it will ignite pre-maturely - pinging. The octane rating is the rating of the compression window of the fuel referenced against pure mixtures of heptane and octane. So a 93 octane gas will give the same window as a mix of 93% octane (a poor igniter) and 7% heptane (a good igniter) - this does not change depending on your continent. Altitude would affect this, but im sure the ratings are referecenced at sea level. As for how they get >100 octane fuels....you got me (probably some extrapolated value)??

davidac · Sep 3rd, 2003, 11:45 PM

I did know that higher octane gas is more stable and has less of a tendancy to ignite under pressure. I belive that is what is known as knock. The explosion occuring before the spark plug fires that is. I was refering to the method of calculation. In the US it is R+M/2 but I think there is also a method called RON and also MON, not that I know what any of them mean. I just know they come up with a different numerical value for the same gas. But if the European method is the same as the US method and you all are running 98 and the best I can get here is 93

no fair.

d2create · Sep 4th, 2003, 02:59 AM

Quote: Originally Posted by davidac

But if the European method is the same as the US method and you all are running 98 and the best I can get here is 93

no fair.

And all this time I thought it was outrageous that gas was so expensive in europe. Now I know why!

In the US we call that stuff 'race gas' and it costs $5 per gallon here too.

KatanaPilot · Sep 4th, 2003, 03:37 AM

Quote: Originally Posted by davidac

I did know that higher octane gas is more stable and has less of a tendancy to ignite under pressure. I belive that is what is known as knock. The explosion occuring before the spark plug fires that is. I was refering to the method of calculation. In the US it is R+M/2 but I think there is also a method called RON and also MON, not that I know what any of them mean. I just know they come up with a different numerical value for the same gas. But if the European method is the same as the US method and you all are running 98 and the best I can get here is 93

no fair.

Hi everyone,

the Octane rating in the US (and Canada) is different from the Octane rating used everywhere else in the world.
As davidac said, in the US and Canada it is R+M/2. The rest of the world just uses the higher one (RON I think). A 93 in the US is probably equal to 97 or 98 elsewhere. I also found that I got slightly better gas mileage using Shell gas.

EBMCS03 · Sep 4th, 2003, 05:39 AM

there are three Octane rating systems, RON, MON, and AKI which is (RON+MON)/2 with MON < AKI < RON.
Here in the US we use AKI and in Europe I've mostly seen RON. Any country use MON ?

For example, BMW recommends for it's K1100 motorcycle: a minimum of 89 AKI, 95 RON, 85 MON.

The MCS I THINK recommends a minimum of 91 AKI which doesnt matter to me cuz thats what i use for all my cars anyways... I drive pretty close to redline a lot of the times and I can use that extra insurance...

bigbaddaboom · Sep 4th, 2003, 09:45 AM

Here is an interesting article on 100 octane fuel, RON, MON and AKI:

http://www.leesracing.com/articles/a3.html

Nic D · Sep 4th, 2003, 02:56 PM

There might be a 100octane rated Shell V Power fuel out soon too, and BP are considering rolling out the same octance level.

I never ever ever use UL and stick to Optimax except where forced to use SUL.

Sep 3rd, 2003, 09:44 AM	#1
duncs MINI2 Newbie Join Date: Jul 2002 Location: West Sussex Local Time: 08:37 PM Posts: 42 Offline	JCW 'S' Fuel Question This has probably been covered in some thread somewhere, although I couldn't find it. I have seen a lot of references around as to how good Shell Optimax is. I thought this was 98 Octane fuel, and from memory I thought that JCW tell you to use 95 to 97 Octane. I use Super Unleaded ( 97 Octane ) at the moment, can I use the Optimax or is it to higher Octane level. Or have I misread or misunderstood something? If I can use it, any comments / reports on the differences to super?. DS/W WORKS S, Cloth/Leather Black Panther, CHILLI, DSC,AUTO A/C, MFSW, CD/RADIO BOOST, XENONS, LAMP WASH, HEATED JETS, OBC.

Sep 3rd, 2003, 10:04 AM	#3 (permalink)
duncs MINI2 Newbie Join Date: Jul 2002 Location: West Sussex Local Time: 08:37 PM Posts: 42 Offline	I assume, having never used anything else that you have had no problems?. Provided I can't find any negative comments, I will give it a go. As opposed to you I have never used it. DS/W WORKS S, Cloth/Leather Black Panther, CHILLI, DSC,AUTO A/C, MFSW, CD/RADIO BOOST, XENONS, LAMP WASH, HEATED JETS, OBC.

Sep 3rd, 2003, 10:32 AM	#5 (permalink)
duncs MINI2 Newbie Join Date: Jul 2002 Location: West Sussex Local Time: 08:37 PM Posts: 42 Offline	Thanks Mate Will give it a go. DS/W WORKS S, Cloth/Leather Black Panther, CHILLI, DSC,AUTO A/C, MFSW, CD/RADIO BOOST, XENONS, LAMP WASH, HEATED JETS, OBC.

Sep 3rd, 2003, 12:27 PM	#6 (permalink)
davidac MINI2 Regular Join Date: Jan 2003 Location: Mass USA Local Time: 03:37 PM Posts: 276 Offline	I know the numbers don't convert directlyto US, or at least I think I know. What is the conversion approximately. 98 octane in the UK is equivelant to what in the US? The hightest octane widely available is anywhere from 92-94 depending ont he station here, but I think those numbers are calculated differently. I am sure someone knows, care to explain? 2004 MCS DS/B

Sep 3rd, 2003, 03:19 PM	#7 (permalink)
duncs MINI2 Newbie Join Date: Jul 2002 Location: West Sussex Local Time: 08:37 PM Posts: 42 Offline	As far as I was aware, the octane rating was a standard number wherever you were. I thought basically, the higher the octane rating the less likely the fuel was to pre-ignite ( due to compression and not the spark ), i.e. reducing effiency. I know that in high altitude countries you tend to get lower octane rating fuel, I guess this is something to do with available oxygen. I know that in south africa around in Gauteng ( approx 2000m above sea level ) that most Garages supply 93 or 95 octane fuel. If I remember in Cape Town ( sea level ) you can get 97 octane. Here in the UK, it ranges from 93 to 97 ( typically ) Optimax is 98. I know this probably doesn't answer your question, I'm hoping there is a budding Chemist out there who may be able to tell me I am talking rubbish and explain the process properly. DS/W WORKS S, Cloth/Leather Black Panther, CHILLI, DSC,AUTO A/C, MFSW, CD/RADIO BOOST, XENONS, LAMP WASH, HEATED JETS, OBC.

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Sep 3rd, 2003, 09:56 AM	#2 (permalink)
Tall bloke Worksssssssssssssssssssss Join Date: Oct 2002 Location: Kent Local Time: 08:37 PM Posts: 204 Offline	I only ever use Optimax in my works s. Can't really give you a comparison, because i have never filled up with anything else (even before the conversion). Chris

Sep 3rd, 2003, 10:07 AM	#4 (permalink)
Tall bloke Worksssssssssssssssssssss Join Date: Oct 2002 Location: Kent Local Time: 08:37 PM Posts: 204 Offline	I have put 18000 miles on my car in a year, and can count on one hand the amount of times i have used petrol other than Optimax. I have had no problems what so ever. Cheers Chris

Sep 3rd, 2003, 10:23 PM	#8 (permalink)
d2create MINI2 Regular Join Date: Aug 2003 Local Time: 02:37 PM Posts: 266 Offline	In the US, most gas stations offer three grades. 87, 89, and 93. In California i believe it's very hard to find anything over 91 due to stricter emissions. So for the US, what octane does the S call for?

Sep 3rd, 2003, 10:40 PM	#9 (permalink)
Critical MINI2 Newbie Join Date: Aug 2003 Location: New Jersey Local Time: 02:37 PM Posts: 47 Offline	Ok, the octane ratings in europe and the US are the same. They are the ability of the fuel to withstand compression-induced ignitions. The higher the octane rating, the more it can be compressed before it will ignite. High performance engines require higher octane fuels because they compress the fuel more before they ignite it (spark). If you put low octane gas in a high compression engine it will ignite pre-maturely - pinging. The octane rating is the rating of the compression window of the fuel referenced against pure mixtures of heptane and octane. So a 93 octane gas will give the same window as a mix of 93% octane (a poor igniter) and 7% heptane (a good igniter) - this does not change depending on your continent. Altitude would affect this, but im sure the ratings are referecenced at sea level. As for how they get >100 octane fuels....you got me (probably some extrapolated value)??

Sep 3rd, 2003, 11:45 PM	#10 (permalink)
davidac MINI2 Regular Join Date: Jan 2003 Location: Mass USA Local Time: 03:37 PM Posts: 276 Offline	I did know that higher octane gas is more stable and has less of a tendancy to ignite under pressure. I belive that is what is known as knock. The explosion occuring before the spark plug fires that is. I was refering to the method of calculation. In the US it is R+M/2 but I think there is also a method called RON and also MON, not that I know what any of them mean. I just know they come up with a different numerical value for the same gas. But if the European method is the same as the US method and you all are running 98 and the best I can get here is 93 no fair. 2004 MCS DS/B

Sep 4th, 2003, 02:59 AM	#11 (permalink)
d2create MINI2 Regular Join Date: Aug 2003 Local Time: 02:37 PM Posts: 266 Offline	Quote: Originally Posted by davidac But if the European method is the same as the US method and you all are running 98 and the best I can get here is 93 no fair. And all this time I thought it was outrageous that gas was so expensive in europe. Now I know why! In the US we call that stuff 'race gas' and it costs $5 per gallon here too.

Sep 4th, 2003, 03:37 AM	#12 (permalink)
KatanaPilot MINI2 Regular Join Date: Jun 2003 Location: Boston Local Time: 03:37 PM Posts: 222 Offline	Quote: Originally Posted by davidac I did know that higher octane gas is more stable and has less of a tendancy to ignite under pressure. I belive that is what is known as knock. The explosion occuring before the spark plug fires that is. I was refering to the method of calculation. In the US it is R+M/2 but I think there is also a method called RON and also MON, not that I know what any of them mean. I just know they come up with a different numerical value for the same gas. But if the European method is the same as the US method and you all are running 98 and the best I can get here is 93 no fair. Hi everyone, the Octane rating in the US (and Canada) is different from the Octane rating used everywhere else in the world. As davidac said, in the US and Canada it is R+M/2. The rest of the world just uses the higher one (RON I think). A 93 in the US is probably equal to 97 or 98 elsewhere. I also found that I got slightly better gas mileage using Shell gas.

Sep 4th, 2003, 05:39 AM	#13 (permalink)
EBMCS03 M5 Extraordinare! Join Date: Mar 2002 Location: So Cal Local Time: 12:37 PM Posts: 6,777 Offline	there are three Octane rating systems, RON, MON, and AKI which is (RON+MON)/2 with MON < AKI < RON. Here in the US we use AKI and in Europe I've mostly seen RON. Any country use MON ? For example, BMW recommends for it's K1100 motorcycle: a minimum of 89 AKI, 95 RON, 85 MON. The MCS I THINK recommends a minimum of 91 AKI which doesnt matter to me cuz thats what i use for all my cars anyways... I drive pretty close to redline a lot of the times and I can use that extra insurance... EB/W MCS Arrived (3/26/03) SOLD 4/25/06

Sep 4th, 2003, 09:45 AM	#14 (permalink)
bigbaddaboom MINI2 Master Join Date: Jan 2002 Location: Brighton, UK Local Time: 08:37 PM Posts: 1,297 Offline	Here is an interesting article on 100 octane fuel, RON, MON and AKI: http://www.leesracing.com/articles/a3.html

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Sep 4th, 2003, 02:56 PM	#15 (permalink)
Nic D MINI2 Master Join Date: Mar 2003 Location: Swansea Local Time: 08:37 PM Posts: 916 Offline	There might be a 100octane rated Shell V Power fuel out soon too, and BP are considering rolling out the same octance level. I never ever ever use UL and stick to Optimax except where forced to use SUL.

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