Regular gas?
#26
#27
Join Date: Jun 2010
Location: Vancouver Island, Canada
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I don't know if the R56's are any different.
Edit: A few links I found say the R56 Cooper has a ratio of 11.0:1, hopefully someone knowledgeable here will chime in
Last edited by dannyhavok; 05-13-2011 at 03:27 PM.
#28
#33
most turbos have a lower compression. Specs for 2011 JCW Clubman says 10:1 compression. Using higher octane gas than what is needed offers no benefit, and can cause issues with "coking" or carbon build up. Octane is added to fuel to resist detonation (so a high compression engine will not "fire" before it is supposed to). It makes no more power than regular gas. Bike guys have this conversation every 3-4 minutes... haha
#34
most turbos have a lower compression. Specs for 2011 JCW Clubman says 10:1 compression. Using higher octane gas than what is needed offers no benefit, and can cause issues with "coking" or carbon build up. Octane is added to fuel to resist detonation (so a high compression engine will not "fire" before it is supposed to). It makes no more power than regular gas. Bike guys have this conversation every 3-4 minutes... haha
Or are you specifically targeting the JCW model with it's "low" 10:1 compression pistons that it doesn't need the high octane stuff?
If the answer to either of those questions is "yes", please don't offer any more advice.
#35
Octane isn't "added", Octane is what gasoline is, i.e. the chemical name of gasoline. 100 octane gasoline would be 100% iso-octane. But the gasoline we buy is really a blend of hydrocarbons that is mostly iso-octane and is blended to act like 87, 90 or 92 iso-octane, depending on where you are.
Dave
Dave
#36
Octane isn't "added", Octane is what gasoline is, i.e. the chemical name of gasoline. 100 octane gasoline would be 100% iso-octane. But the gasoline we buy is really a blend of hydrocarbons that is mostly iso-octane and is blended to act like 87, 90 or 92 iso-octane, depending on where you are.
Dave
Dave
#37
most turbos have a lower compression. Specs for 2011 JCW Clubman says 10:1 compression. Using higher octane gas than what is needed offers no benefit, and can cause issues with "coking" or carbon build up. Octane is added to fuel to resist detonation (so a high compression engine will not "fire" before it is supposed to). It makes no more power than regular gas. Bike guys have this conversation every 3-4 minutes... haha
But an engine's octane requirements are determined by the dynamic cylinder pressure during compression and combustion, and forced induction makes a huge difference in dynamic cylinder pressure.
If you have a naturally-aspirated engine with a 7:1 static compression ratio, you can probably safely run it on any crap gas that will burn. But take that same engine and attach a turbocharger running 25-30 psig of boost, and your fuel requirements will get real strict real fast, even though the static CR is still 7:1.
And 10:1 isn't "low compression" to begin with. If not for things like proper cooling, good combustion chamber design and aluminum cylinder heads, that kind of a ratio would probably require premium gas even without the turbocharger adding to the dynamic cylinder pressure.
#38
I just knew some smartass would say something like that! OK, I'll go into a little more depth.
It is possible for an octane number to be higher than 100 because of the varying methods they use to calculate the octane number.
Octane is also a measurement of the resistance of a fuel to cause engine knock, or pre-ignition. You can add chemicals, methanol, ethanol, toluene, zylene, methyl tertiary butyl ether and tetra-ethyl lead to iso-octane that will push the resistance to pre-ignition to higher levels than just octane can provide, hence the possibility of higher numbers than 100 octane.
Dave
It is possible for an octane number to be higher than 100 because of the varying methods they use to calculate the octane number.
Octane is also a measurement of the resistance of a fuel to cause engine knock, or pre-ignition. You can add chemicals, methanol, ethanol, toluene, zylene, methyl tertiary butyl ether and tetra-ethyl lead to iso-octane that will push the resistance to pre-ignition to higher levels than just octane can provide, hence the possibility of higher numbers than 100 octane.
Dave
#40
#41
#42
Good question.. I don't think theres any way to tell what they ran in the car prior unless you're buying from the previous owner
I bought a 2013 R56 a couple months ago and I have been running premium in it ever since. But I bought it from a dealer so I have no Idea what was used in it for the previous 49000 miles.
I bought a 2013 R56 a couple months ago and I have been running premium in it ever since. But I bought it from a dealer so I have no Idea what was used in it for the previous 49000 miles.
#44
Do not run 87 octane in your Cooper, it'll run like crap. Really your are putting at the most 12 gallons in the car and that's if you area really empty. At $.20 more then regular, premium will cost you at most $2.40 more per fill up, that's nothing in the grand scheme of things. If money is that tight just skip a morning coffee or some other unneeded expense from your week.
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DexterBaxter (02-21-2020)
#46
Do not run 87 octane in your Cooper, it'll run like crap. Really your are putting at the most 12 gallons in the car and that's if you area really empty. At $.20 more then regular, premium will cost you at most $2.40 more per fill up, that's nothing in the grand scheme of things. If money is that tight just skip a morning coffee or some other unneeded expense from your week.
#49
I ran 87 once, and it was fine, but I noticed a little bit more hesitation when letting off the clutch from a dead stop. Probably the computer getting used to a less-than-expected octane level, or something. Generally, you don't want to be cheap about gas, thanks to the ethanol content, which WILL gum up your intake over time. At least go with midgrade. I normally run REC-90, 91 or 93. I know that sucks to hear when we're living in a completely self-made oil crisis, but at least you can get 40-50mpg out of these cars. It evens out somewhere, I'm sure.
#50
It's not recommended by BMW, but my sister has used nothing but regular in her 2018 Countryman S, and it is doing fine. She uses mostly Costco gas, which is "Top Tier," and should have the additives DGI engines need to keep the valves, etc. clean. The mildly tuned, low boost 189 hp MINI engine should not need premium, when more powerful 2.0 turbos from other companies use regular.
Last edited by KitGerhart; 07-10-2022 at 06:28 AM. Reason: to add more info
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