Been told 89 by the selling dealer, I use 93 in the coupe, but a fellow JCW owner told me more bang in his with 89..anyone? Would switch both the n14 and n18 to 89 if it works :-D
Thanks

 

IMO, the higher the better. Out here high test is 91 octane. But whenever I hit the track, I run 100 octane.

I'm pretty sure MINI calls for premium fuel only. But that's not based on me reading my manual. Just from years of owning BMW's.

 

MINI revised the recommendation from 91 down to 89 last year on the turbo cars. Yes, the car will run on 89 as the knock sensor will adjust the timing to compensate. But it will also potentially reduce power output and contribute to carbon buildup.

 

Interesting. But until I hear from others about how great it is, I'm sticking with the high test.

 

Sticking with 93...

 

91 octane is 3.70$/gal

93 octane is 3.75$/ gal

That works out to a whopping 50 cents@10 gallons/fill up.

I think my car is worth an extra 50 cents.

Let's face it, 50 cents on top of almost $40 is trivial.

 

To add what Dan said, you get slightly less MPG with the lower octane, so the savings at the pump is even less.