I'm considering a 2008 Mini (clubman), and am wondering what you MINI owners typically use in your cars. Premium, standard? Any significant difference in mileage with one v. the other? Thanks!

 

You have to use premium with the S type for sure. It all has to do with the compression ratio. Im not sure about the base engine although i think it too requires premium. Using standard will cause the engine to retard the timing to prevent knocking which reduces power and gas mileage. If your car doesnt need premium, dont get it, you are just wasting your money.

 

MINI recommends 91 Octane. I can never find that so I use 93. Some folks use a 93/89 mixture, but I'm not sure how well that really works.

 

you should use the highest octane that the pump has to offer, Mini recommends a minimum of 91 octane. Here in Oregon we have 92. The compression ration of the engine requires the higher octane gas to achieve it's optimal performance.

 

How much money are people really gonna save by mixing 89 and 93 octane? I though people would have gotten over the gas price paranoia by now. Prices going up is ancient history. Just use the highest you can find.

 

exactly! my stance is to just use the highest that's available. If we had 93 here, that's what I would use.

 

Check out this thread also. I'm testing out 87 octane.

 

The OBC will adjust the spark for 87, but you will be down on power. My guess is that you will get less mpg.

 

I wonder if there would be a difference between performance/efficiency degradation between the MC and MCS when using lower octane fuel?

 

ghosthound is correct, use whatever it says in the manual. Using higher octane than rated only helps if you are getting pinging/knocking (pre-detonation). Most cars nowadays have an anti-knock sensor anyway and it isn't much of an issue AFAIK. Higher than needed = waste of money.

 

I think that 93/89 thing is people taking MINI's recommendations waaaaaaaaaaay too literally. The reason MINI recommends 91 is that in some states it is the highest octane you can buy.

 

I saw the Clubman at the launch at my dealership last night. Very nice. I love the chocolate brown.

 

Is it that simple? Since the OBC can adjust the spark for the octane, could it not take advantage of the higher than 91 fuel? Some of the competition folks go looking for 100 octane...

 

The manual does say premium for R56 Cooper. Yes, the computer will adjust for lower octane gasoline, but consider this: gas mileage and performance will be down and if you put 10 gallons in the car you will save $2.00. Just doesn't seem worth it to me.

 

Is anyone going to comment on the whole "top tier gasoline" issue? My dealer (MINI of St. Louis) has a sign up in their service area listing the gas stations that they recommend. Supposedly, top tier gasoline has the appropriate detergent mixture for a MINI. After reading a lot of threads on other motoring sites, I really cannot decide if it is necessary or just marketing hype.

 

This page explains it pretty well:
http://theserviceadvisor.com/octane.htm

 

Possibly, but it is ten years old.

 

IIRC, there have been some threads here reporting problems that resulted in using lower quality gas. I think I'll spend the extra $0.20 per tank and stay with Shell.

 

If I had a MCS, I wouldn't dare try using lower octane stuff, but feels strange to use premium for just a cooper.

 

FAQ:

Q: Is Top Tier Gas marketing?

A: Yes. But their standards exceed US EPA and my state's regulatory requirements in several areas. See http://toptiergas.com/deposit_control.html for a list of their standards.

Q: Does it make a difference in a MINI?

A: It can. Some NAM members (including me) have had trouble with premium fuel from low-price retailers. Ethanol (EtOH) is a relatively inexpensive oxygenate, and retailers selling high octane product will sometimes sell formulations with more than 10% EtOH. Your owner's manual says this may cause engine problems and risks damage to your fuel system. That is true. It also voids your engine warranty. That is also true.

Q: Are you kidding me?

A: No. In my state it is unlawful to sell gasoline with > 10% EtOH unless clearly marked on each pump. The penalty is $1000/day/pump. That did not stop a "value" local-brand retailer from selling me 15% EtOH gasoline without my knowledge. It destroyed my fuel pump, and cost me just over $1500.00 in repairs and other costs, out of warranty, as tests showed the fuel contained excessive EtOH.

Q: No! Really?

A: Yes. My local MINI/BMW dealer sees several of these every quarter. I was told they have seen as much as 17% EtOH in a fuel tank, though 12-15% is more common when problems bring cars in. In my case the fuel distribution co. eventually settled with me out of court, but that was an unexpected happy ending, so I would not wish this experience on others.

Q: Wow. So, what fuel are you buying now?

A: Still 93 octane, but only from top tier retailers.

 

I'm used to 93--last few cars have required it--so it's no big deal. That's the lowest I would use, and I generally stick with Shell or Texaco.

BTW, I saw an ad on television that said Shell was giving away a microfiber cloth with a 10 gallon fillup of premium. I think it was Houston area, but I have satellite, so it might have been anywhere. Haven't tried it yet, but if it's true, there'll be a pile of 'em in my garage! Worth asking about it...

 

The engine in "just a cooper" is a pretty sophisticate one.

 

I got the car for it's good looks and parking in the city, not really for it's mpg or engine performance. I have fallen in love with it's handling and pleasantly suprised with it's pep. Getting regular is reverting to old, comfortable psychology. With my driving, I don't think premium would make much of a difference. Haven't noticed anything yet. This thread is activating my OCD, though.

 

Premium for my turbo jet.

 

Is there another determinant when choosing octane rating other than compression ratio? If not, then why the distinction between the MCS needing higher octane that the MC? The MC actually has a higher compression ratio (11:1) than the MCS (10.5:1). Does the turbocharger change all that with regard to pre-ignition?