Most of the reasons I can think of would also cause the OBD to throw a failure code and illuminate your "check engine" light. How many miles are on the car? How long has your supercharger belt been on the car? (it may be slipping) Do you always have the hesitation, or does it come and go?

 

I have a 2005 Mini Cooper S and I notice it too. The flywheel on the car is rediculously heavy and it tends to put alot of strain on the engine untill the super charger kicks in at around 3,500 RPM. If you are babying the car you'll notice that lag alot more in hte middle, if you are impatient like me, you'll just rev the engine up high and feather the clutch to keep the RPM's up. This could be why i needed a new clutch and front end at 50,000 miles
Doing this for some reason,tends to foul up your spark plugs pretty quickly and that gave me some major acceleration problems. Try changing your plugs and see if that helps

 

I wouldn't even consider running anything but (Super Unleaded) or (Premium Unleaded) in any MINI or anything else - except for maybe a lawn tractor...or a weed whacker....

 

Well I didn't read this entire post because it's a mile long. But in a nutshell, Mini's have a high compression engine which is why they need a higher octane. Any engine that has a compression ratio above approximately 9 to 1, will need a higher octane fuel. Higher compression engines need a slower burning fuel which is provided by the higher octane rating!

 

Too much coffee is not always a good thing!!!

 

Mine has never seen anything less than 93 octane, it still runs marvelous @108K.

 

People,
Think of where the engine was designed and built (Europe). There the petrol sold is 93 to 105 octane. Think ! also there gas is aprox $9 a gal.
So there 93 is low octane.

 

Apples to oranges
RON vs AKI

Explanation taken from Wiki...

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


Anti-Knock Index (AKI)

In most countries, including Australia and all of those in Europe, the "headline" octane rating shown on the pump is the RON, but in Canada, the United States and some other countries, like Brazil, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI, and often written on pumps as (R+M)/2). It may also sometimes be called the Road Octane Number (RdON) or Pump Octane Number (PON).


Difference between RON and AKI

Because of the 8 to 10 point difference noted above, the octane rating shown in the United States is 4 to 5 points lower than the rating shown elsewhere in the world for the same fuel. See the table in the following section for a comparison
RON MON AKI
"regular" gasoline in Australia, New Zealand, Canada and the US 91–92 82–83 87
"EuroSuper" or "EuroPremium" or "Regular unleaded" in Europe 95 85–86 90–91
"SuperPlus" in Germany, Great Britain, Slovenia and Spain, "SP98" in France 98 89–90 93–94

 

yeah

 

 

Ha ha ha ha !

 

And they can prove that how?

 

As posted on other threads, regular gas as opposed to premium isn't a lower grade fuel. It just has lower anti-knock properties as the octane rating suggests. There is more potential power in lower octane but higher compression/more timing advanced engines can't use it to its full potential due to knocking/predetonation. So the perfect fuel is the lowest octane rating that allows your engine to run as timing advanced as it needs for best performance without predetonation.

 

it's very easy for them to take a fuel sample and have it analyzed. Doesn't meet minimum octane? bye bye warranty no matter how much you cry.

 

Really, , , wouldn't they need to prove that lower octane was used ALL THE TIME and not just one tank? What if just THAT ONE TANK was higher octane and lower had been used the rest of the time? They are going to test every mini that comes in for work? Seriously? It defies logic.

 

you are naive. They don't need to prove you ran it all the time - just the tie you brought it in and a problem was caused by low octane.

You come in for detonation faults.. They very well might run an octane test - they are troubleshooting the car and need to find out why there is detonation. If they test it and the octane is low - you just got yourself a service bill.

Blow a hole in the piston? Dang straight they would test the gas if they didn't find any mechanical problems for it happening. The computer would already have a string of knock detections saved. You think you'll throw some premium in there after blowing a piston to cheat the gas test? unlikely.

Stuttering/stalling/hard to start problem? They look at the injectors - Are they clean? Fuel pressure good? If yes, test the gas and charge the customer if it's bad..

Dealerships can easily and cheaply get gas tested. Of course they will if that is a possible cause of whatever problem you've had and there are no other obvious reasons or the obvious reasons have already been disproven.

 

Not good enough, I'm fairly confidant that a Judge would uphold their requirement to fulfill the warranty unless there was a direct correlation between lack of responsibility on the consumer's part and failure of the mechanical equipment.

 

go ahead and run whatever you want. Please post when you have to pay a repair bill so i can laugh at you.

 

Don't forget the Chevron Techron additive to help remove the combustion deposits.

 

Higher oct is the temp that fuel burns a high compression engine causes more heat in the compression stroke the gas burns before the plug fires causing a knock and yes the computer changes timing to help out but some performance is lost Cleaners are added to fuel to keep your injectors clean not for a knock problem The higher the engine compression the higher the oct
rating that in needed

 

first and best

 

What he said

 

Every 4k miles.....

 

It's a lot cheaper than removing the head to clean the valves...

 

would a non-ethanol 91 octane gasoline be acceptable run in a cooper s?