[teddyx]

What petrol do y'all use in your MCS's??. Mine's two days old and I want to wean it properly! My dealer recommended Shell optimax
but I'd like to hear your opinions. Cheers
Phillip

[tonyp]

Super unleaded in the US 93-Octane works with the performance and supercharger.

[BillK]

Quote:

Originally posted by teddyx
What petrol do y'all use in your MCS's??. Mine's two days old and I want to wean it properly! My dealer recommended Shell optimax
but I'd like to hear your opinions. Cheers
Phillip

I recommend you do a search of the discussion groups. There was a thread on UK petrol brands a month or so ago. I am pretty sure it was not under Interior and ICE though.

MINI specifies 91 octane, and there was a clear consensus to avoid cut rate and supermarket gas as it is inconsistent.

[XSmall]

I'm curious about this in the US, I've been wondering if I should use the premium gasoline. I'm a little ignorant about fuel, and don't really know what the difference is. Is it worth the extra $$?

[BillK]

Quote:

Originally posted by XSmall
I'm curious about this in the US, I've been wondering if I should use the premium gasoline. I'm a little ignorant about fuel, and don't really know what the difference is. Is it worth the extra $$?

The octane rating deals with the amount of anti-knock compounds in the gasoline. If you use a gasoline with insufficient anti-knock compounds, you will over time damage your engine and you will hear "pinging" as you drive, particularly during acceleration and up hills. This does not mean everyone should use Super, it means you should use the grade recommended by the manufacturer. of course, for the MINI, that IS Super.

As I stated above, there are other threads on this subject, and if you read them you will see some of the problems others are having because they are not using the right gasoline.

[stryder]

Quote:

Originally posted by BillK


The octane rating deals with the amount of anti-knock compounds in the gasoline. If you use a gasoline with insufficient anti-knock compounds, you will over time damage your engine and you will hear "pinging" as you drive, particularly during acceleration and up hills. This does not mean everyone should use Super, it means you should use the grade recommended by the manufacturer. of course, for the MINI, that IS Super.

As I stated above, there are other threads on this subject, and if you read them you will see some of the problems others are having because they are not using the right gasoline.

Essentially correct, however the MINI (both of them) have anti-knock sensors, so you'll actually cause your engine to run weaker (lower compression) automatically before you damage it because of too low octane. (In theory at least).

With regards to the original post:
Calculate the cost of super vs. regular, its at most $.20/gallon. Say you drive ~10K miles/year, which is 250/week, or about 10 gallons (assuming good milage) That's an extra $2/week on gas, or $110 a year. You just bought a car that cost over $20k. The least you could do for the poor thing is give it the gas it needs. Saving money buy decreasing the performance of your car and potentially damaging it would make sense if it was thousands of dollars. Its not.

[BillK]

Hmmm . . . I see the thread has been moved to a more appropriate foum. Thanks!

Quote:

Originally posted by stryder


Essentially correct, however the MINI (both of them) have anti-knock sensors, so you'll actually cause your engine to run weaker (lower compression) automatically before you damage it because of too low octane. (In theory at least).

With regards to the original post:
Calculate the cost of super vs. regular, its at most $.20/gallon. Say you drive ~10K miles/year, which is 250/week, or about 10 gallons (assuming good milage) That's an extra $2/week on gas, or $110 a year. You just bought a car that cost over $20k. The least you could do for the poor thing is give it the gas it needs. Saving money buy decreasing the performance of your car and potentially damaging it would make sense if it was thousands of dollars. Its not.

Nice to know about the sensors Stryder, thank you.

I believe Teddyx is in the UK, and petrol is quite a bit higher there, but overall I agree, a few quid more on petrol is worth it to take care of your new car and enjoy its full potential.

[GordonD]

Quote:

Originally posted by BillK


I recommend you do a search of the discussion groups. There was a thread on UK petrol brands a month or so ago. I am pretty sure it was not under Interior and ICE though.

MINI specifies 91 octane, and there was a clear consensus to avoid cut rate and supermarket gas as it is inconsistent.

I realize I am a bit late on this thread but I thinkit is worth noting that 91 octane is the minimum for an S. According to the M-Z artcile is is optimized to run on 98 RON.

I don't think you can buy this in N.A. except at a track. Sunoco 94 is the best you can get in Canada - I'vwe been running it since July and feel it is worth the very slight premium over 91/92 octane at other stations

[cordial]

Quote:

Originally posted by stryder


Essentially correct, however the MINI (both of them) have anti-knock sensors, so you'll actually cause your engine to run weaker (lower compression) automatically before you damage it because of too low octane. (In theory at least).

You are correct, all (three) MINIs have "knock sensors". Using lower octane fuel does not reduce compression but adjusts the ignition timing which reduces power output thereby preventing knocking. Conversely, using the higher octane means getting more power output. I can't get enough of it, so I'm using Shell SUL 98 (Optimax is not sold here sadly).

The compression ratio cannot be altered without physical modifications i.e. changing the stroke or bore of the cylinders.

[Martin L]

Shell Optimax
It's a performance car which needs high octaine fuel and Optimax is the cheapest and highest Octaine (nearly 99 ron)

[stryder]

Quote:

Originally posted by cordial


The compression ratio cannot be altered without physical modifications i.e. changing the stroke or bore of the cylinders.

We're making progress on this all the time. (mostly by pointing out flaws from other people) I completely forgot that the MINI doesn't have variable valve timing when I wrote that, which would also allow for performance changes as well. Somehow I had compression on the brain. Thanks for bringing that up.

I should also mention we're having gas octane issues based on the difference between RON and MON, US gas (Canada too if I recall) is rated as the average of the two, other places tend to not do that which can make their octane seem higher. As far as I know its nearly (or economically/legally) impossible to make unleaded gas higher then 94 or so (R+M)/2 since certain stations (Southern California mostly) sell 'low lead' which is like 98 or 100, and leaded which is 108 or so. They label it for off road use only, so they avoid any legal problems with still selling leaded gas.

(Link about RON + MON here: http://www.refiningonline.com/Engelh...ep/TCR4_29.htm )

[cordial]

Quote:

Originally posted by stryder


I completely forgot that the MINI doesn't have variable valve timing when I wrote that, which would also allow compression changes. Thanks for bringing that up.

Stryder, don't take it personally! We ALL learn something from this site so we should all try to keep it as correct as possible.

Oh and VVT has no influence on the compression ratio. It just does what it says: it varies the timing of the opening and closing of the valves. The compression ratio is measured when all valves are fully closed.

[stryder]

Quote:

Originally posted by cordial


Stryder, don't take it personally! We ALL learn something from this site so we should all try to keep it as correct as possible.

Oh and VVT has no influence on the compression ratio. It just does what it says: it varies the timing of the opening and closing of the valves. The compression ratio is measured when all valves are fully closed.

Trust me, I won't. I wasn't being sarcastic, I actually found it sorta funny how its progressing.

And I thought more about the post, so as you can see, I actually edited it 5 min after I posted the reply and changed it to not say vvt had anything to do with compression. Its 5am here and I haven't gone to sleep because I'm not tired, I think my brain's stopped functioning in any case so I'll try to sleep now.

[YaST]

Quote:

I realize I am a bit late on this thread but I thinkit is worth noting that 91 octane is the minimum for an S. According to the M-Z artcile is is optimized to run on 98 RON.

There is a high octane gas staion right down the road from me here in Santa Monica, CA. It has around 98, 103, 106 Octane... but prices run from $3 - $6 a gallon. I highly doubt putting in any of those octanes would show any performance boost over 92-93 in the S, unless it had 11+ compression ratio.

[sugster]

I run my One only on super unleaded which has an octane rating of 98. This is the maximum octane rating you can buy in the UK (at least I've never seen anything higher).

The standard unleaded is rated at 95. I've noticed that it runs much smoother on superunleaded, it may be a little faster too, but I'm not too sure on this - could just be my imagination. Haven't really noticed that fuel consumption is any different. The superunleaded does help to keep the cylinders cleaner apparantly.

In the UK there is a 5p/ litre price difference between the two types of petrol. In my area regular unleaded is 74.9p/l, super is 79.9p/l.
Convert that to $/gallon and you realise that you americans are on to a good deal!

[stryder]

Quote:

Originally posted by sugster

In the UK there is a 5p/ litre price difference between the two types of petrol. In my area regular unleaded is 74.9p/l, super is 79.9p/l.
Convert that to $/gallon and you realise that you americans are on to a good deal!

I agree, I have zilch to complain about when I can fill up on 93 (M+R/2) for like $1.40/gallon. I haven't even bothered filling up with anything else, since for $.20/gallon its not worth being mean to the car.

[McprS]

Optimax whenever I can get it.

[Bruce M]

Optimax is a Shell product. Basically their Super Unleaded option but developed to the next level. Reduces build up of deposits on the backs of valves and inside fuel injectors.
I plan to use it where possible when I get my MCS.

[erichui]

i have been only using super unleaded for the car.
i myself uses the BP Ultimate whcih in australia has the same octane as the Shell optimax.
however i found that BP is a bit smoother on the enigne

[KAS_COOPER]

Quote:

Originally posted by erichui
i have been only using super unleaded for the car.
i myself uses the BP Ultimate whcih in australia has the same octane as the Shell optimax.
however i found that BP is a bit smoother on the enigne

How can you state the BP "is a bit smoother" than Shell.

It's all in the mind !!

Or so my psychiatrist keeps telling me !!!!!