I am a new (just 1month) mini owner. ? the first time I got gas I filled up with reg and then saw on the cap door (min 92) (premium), that tank I got 32MPG, next fill I uses premium, that tank I got 35MPG. So ? how important is it to always use premium? thanks for the advise, what is the average MPG, Is my mini doing okay? thanks again and have a great cooper day.

 

Welcome! Lots of posts about regular vs. premium. The better gas mileage was a result of the computer taking advantage of the higher octane and increasing the timing for more power and fuel efficiency. For me it's a no-brainer. For just a little bit more per gallon you get the best mileage and power, plus it's what MINI requires.

 

Congrats on the new car! We all like pictures here. Hint, hint.

The cars are engineered to operate on the higher octane gas and regardless of gas mileage the requirement from MINI is that you use premium fuel. I would not want to test what might happen if it was not used. Maybe nothing, maybe something significant.

 

Regardless of what vehicle you put it in, a higher octane rated gas let's the engine run smoother and will always result in better MPG. You can run your Mini with Regular, but you will see a marked loss in performance.

 

The owners manual says you can use reg. fuel if premium is not available - but I would not use it for any extended period of time. Over the long run it may cause issues with pre-detonation if the octane is to low.
Premium fuel is cheap insurance ( or an octane booster )

Good luck and enjoy your MINI

 

These three websites will help you out. Put the URLs in your MINI favorites folder if you haven't already opened one. The pure gas list is a great help when traveling. Many station listings include GPS and a map. Hope this helps.

#1: http://www.toptiergas.com/

#2: http://pure-gas.org/index.jsp?stateprov

#3: http://soopercooperinfo.com/

Almost forgot. Another must have URL: http://www.motorcycleroads.us/index.html

 

In days of old when cars did not have knock sensors cheaper gas may have predetonated but you may not have noticed it. With knock sensors the higher octane will allow advanced timing. Reg gas will result in less advanced timing and lower mileage. For me, with my MCS it is higher octane, Top Tier gas.

 

Thanks everyone

 

"MINI Division requires the use of premium fuel (91 AKI) only if you want to duplicate the official EPA certified emissions and fuel economy. However, if you choose to use less than 91 AKI (it is not recommended to use below 87 AKI), it will not harm the engine. It is important to note that there will be a reduction in fuel economy and performance and emissions will increase."

The above quote is from MINIUSA via email and is specific to my normally aspirated 2010 Cooper. Note that 87 is NOT recommended for an "S" model per the owner's manual. I am not seeing a drop in mpg when I use 89 nor can I detect any degradation in performance. I haven't tried 87.

As for mileage I average 37.5 on 175/65-15 OEM ContiPremiumContact 2 tires and 34.0 on sticky 205/50-16 Dunlop Star Specs. Mileage will take a hit with the A/C on.