I never run anything less than super. I ran 89 a few times and you could notice much more pinging under acceleration. Maybe just psychological but I feel better running my local 93 all the time.

 

yes. $4300.

 

Around here, 91 octane is 60 cents higher than 89 octane.

 

In both my mcs I have only run 91, that's because I had a turbo Audi that I tried to be cheap on an it cost me $5000 to repair the engine damage!

 

I didn't even realize it was a premium engine when I got mine (2005 R50).

I ran it for ~10,000 miles on regular 87 octane fuel - then one day saw the sticker on the fuel door saying "Premium 91 octane only". I immediately switched over and...

There has been absolutely no difference. Gas mileage - same. Power - same. Engine noise - same. Still, it is the fuel the engine was designed to use, so I don't mind paying a couple bucks extra. I still get about 36 to the gallon, so I'm not complaining.

- Ald

 

I had the same experience....bought mine from a guy here ...an 02 R50, the first day I got it the clutch went out and had to be replaced...I was on my way to the gas station to fuel up and didn't get to know that until 2 weeks later when I got the car back...been running 93 up until a couple days ago when I had to put in 89 ( non ethanol) my mileage actually went up and my car runs quieter and smoother.......not sure what that is......I'm probably going to go back to 93 ( that's what we have here in eastern NC) 93, 89 and 87.......but the non ethanol 89 gave me pause......Love my mini though

 

Non ethanol will give better mileage because it has more units of energy (BTU's). Ethanol is designed to replace fossil fuels. A 10% blend of ethanol typically affects mileage in roughly the same proportion. So there is no $$$ savings, just savings of fossil fuels (at least in theory).

If you don't drive hard, don't worry about the lower octane. Cruising on the highway use what you want. But if you are driving the car the way it was meant to be driven , 93 is the better choice. IMHO.

Regards,
Jerry