Hi ~ I just traded in my 2007 CooperS on a 2013 Justa. The dealer (Niello Mini) in Sacramento said to use mid-grade gas but I hesitate to use it. He said it wouldn't hurt the engine at all. The manual contradicts itself . Gasoline quality: manufacturer recommends aki 91. Minimum fuel grade: manufacturer of your mini recommends aki 89. I am approaching my first fill up and wanted to get your opinions.

 

the computers on the engine will compensate for the octane you use

if you use lower octane than the engine was designed for, the computer will compensate but you'll lose some HP . . .

owner's manual of my Focus ST explains it MUCH better than MINI does and provides a chart of max hp (possible) by octane rating . . . . from top to bottom the range is only 10hp .... (250 hp turbo engine btw . . )

but I see folks buying many MINI gizmo's to gain 10hp . . . so maybe it matters to you ...

***
do you know what 'octane' means .. or IS?

read up on it a bit and you can make an informed decision . . .

 

Can't really help you make a decision but if the manual says that the minimum grade is 89, it probably will not hurt it. Just don't put 87. Btw, I aslo purchased my '13 MCS from Niello!

 

I received the same advice from my dealer. Since then mid range is all I have used and 15k miles down the road I have no problems to report.

 

My dealer told me it was OK to use regular in my S. Not in my car. Our non S gets high test too. The difference in cost is not much. Your MINI has a knock sensor, so if you have to buy regular you won't kill it. You will lose performance using it. In an emergency regular other times high test. Just my .02.....

 

The Cooper non S is actually higher compression than the Cooper S. So in my opinion it is even more important to use premium fuel.

FYI do the math on average it's $200 or less a year to use premium over mid grade. Such a small difference in cost. It's not worth it to be cheap as the car will run better on the premium and get better mileage.

 

What I have experienced is improved performance and increased gas mileage in almost every car I've ever owned using premium. My net fuel cost was no less using premium and the little extra performance was a bonus.

I have also found a big difference in both performance and gas mileage based on brand.

 

This guy at work has an escape titanium 2.0L turbo. His manual calls for regular 87 so that's what he puts in it. Probably could gain a few hp with premium but he doesnt care.

 

If memory serves me there was a previous forum thread that discussed various engines. It basically said that when MINI modified the original Prince engine in 2011 the Cooper (non-S) version was modified to allow for mid-grade fuel. I believe all turbo versions, and 2007-2010 R56 Coopers, call for premium fuel.

Prince Engine Minimum Fuel Recommendations
N12 (2007-2010) Cooper: Premium
N14 (2007-2010) Cooper S: Premium
N16 (2011+) Cooper: Mid-Grade
N18 (2011+) Cooper S: Premium

 

I ran 89 and 91 in my base 2010 MINI. Here are the mpg results on 175/65-15 ContinentalPremiumContact 2 tires:
grade miles gallons mpg
91 6971.5 186.18 37.45
89 2633.4 70.45 37.38

And on 205/50-16 Dunlop Direzza Z1 Star Spec's:
grade miles gallons mpg
91 5916.2 172.60 34.28



I used 91 when I autocrossed. On the street I could detect no difference in power between 89 and 91. MINIUSA via email said the contradictions in stickers on the gas cap on my 2010 (91 required) and the manual (91 recommended, 89 and 87 ok) were caused by EPA regulations governing the sticker.

The sticker on my gas cap on my '14 Roadster S says unleaded premium 89 minimum. So far I have only used 91 averaging 32.9mpg.

 

In my experience, all cars benefit from the premium gas. It may cost 10% more than the cheap stuff, but I typically get 10% better gas mileage. Plus the extra additives, it's good for the car. The math holds true for my wife's SUV too. I've done the pepsi challenge, her mpg improves from 16 to 19.

 

OK Way, this one blew my mind

The Cooper non S is actually higher compression than the Cooper S.

but I went into my GEN1 books and at least for the GEN1 I see you are 100% correct (big surprise there)

So can you please explain the difference 'tween a higher compression engine versus a lower compression engine with a device to increase the pressure???? This is a part of the equation I've missed up to now. Inquiring minds want to know!!!

(given that OCTANE indicates a resistance to self ignite so more pressure requires higher OCTANE to prevent pre-ignition aka knock)

 

While it is true that the S turbo version has lower compression that calculation is based purely on the mechanical physics of bore stroke and compressed cylinder volume in a non-running engine. It does not include the added pressure of forced induction air from the turbocharger in a running engine.

 

I haven't made a comparison but I've always felt that the people writing the owners manual knew more about the subject than I did.

 

These vehicles are very sensitive to the type of gasoline quality used (especially the N14 engine). I recommend 91 octane top tier gasoline in every vehicle (even non-S), such as Chevron or Shell.

 

Avg of 35-36mpg on trips with 93 octane.

 

Octane is a +/- thing by 2. Your Mini will compensate for the actual octane level. But with that being said......I use only 93 grade. Where I live there is no 91 and the next level is 89.

 

I'd have to look at the pump to verify, but i'm pretty sure they list the min octane (aki in the US). So it could be higher but not +/- 2.

Sent from my XT926 using NAMotoring

 

I can eat McDonald's every day and stay alive, and if it's that or starve, it's what I'll do... but I sure run better on chicken, broccoli and brown rice.

Also, I get more KM out of a tank on 94 than I do on 91 with the same commute. Not quite the scientific method, but for a few bucks it can't hurt.

 

89 is correct for newer coopers. I use 93 exclusively in my '13 MCS. I agree with the McDonalds sentiment.

 

You can eat healthily at McDonalds if you want: http://sploid.gizmodo.com/man-loses-...lds-1496972541 I wouldn't survive very long on broccoli and brown rice.

MINI recommends 91 (and 93 for a JCW), so that's what I use (we don't have 93 around here for the JCW though). They say the minimum is 89. I'm assuming by recommending the higher grade the engine can actually make use of it.

 

I don't see that as a contradiction. They're saying they think it's best to use 91 AKI, but that you can use 89 AKI. And you shouldn't use anything lower.

I run 91 in my Justa.

 

I have a 2012 Justa and a 2013 Justa

My wife only drives about 6K miles per year, mostly short trips, so the car doesn't really warm up very often. There is no difference in mileage with either octane level due to not often achieving optimal operating temperature, so we use 89 in that car.

She averages about 32mpg.

I drive about 25K per year. I started with 89 and switched to 93. I experienced a pretty nice increase in mileage

89 = 37.2
93 = 38.8 MPG

Please keep in mind I live in Fla.. very flat, wide roads and very consistent temperatures and humidity levels so it is very conducive to good mileage.