Hi there. I am not even a Mini owner, but I hope to change that in the next 6 months, once I can get an '07 ordered, then it's a matter of picking a color on my hardtop MCS. Yay!

I was wondering if anyone knew how crucial premium gas was compared to regular or even mid-grade? I've always driven a Honda civic, and it's not so picky, and several folks at my work say that their cars say "Premium Gas Only" but they still use regular without problems.

Without casting judgement on them, for they own not Minis, can others share their expertise in regards to the importance of fuel grade when it comes to the MCS?

Thank you! I'm sure I'll have more questions shortly. I research these kinds of major purchases exhaustively...

JMelrose

 

I would follow the recommedations of the owner's manual. BMW isn't in the business of selling gasoline, and has no reason to recommend a higher grade than is necessary.

It's entirely possible that your friends have been running lower-than-recommended quality gasoline with no "problems", because just about any modern car that requires premium fuel also has a "knock sensor" that will detect detonation and knocking from the use of low-octane gasoline and adjust the ignition timing to stop the detonation.

This will allow the engine to run safely with the lower-octane gas, but you won't be getting the full performance out of the engine, and I don't think that driving around with the ignition settings constantly in the "cheap gas mode" is good for emissions levels or the long life of your engine.

Scott

 

Check this post for 11 pages of discussion on the topic.

 

I'll sum it up... 15K miles a year at 25MPG = 600 gallons of gas

x 20 cents extra for 93 octane = $120 a year difference ($10 a month)

Is it really worth going against the manufacturer's recommendation for the price of two lattes?

 

Good points made above. Living in California, it's just hard for me to pay $3.50/gal regardless of what MINI says. I ran the lower octane once... the car ran like crap. Knocking & sluggish... Long story short... I paid $3.50/gal!

 

It's a fair question, Mark. :-) I'm actually more curious because I know when I tell my spouse that the car runs on premium, there will be flippage. Just want to have my facts in hand.

 

Welcome to NAM, J!! Yup...it's better for your engine and MINIs get better fuel economy on premium. Do it and don't look back!! Heck, on top of that I only consider top-tier gas for use in my MINI!!

 

Good luck with your spouse! Feel free to use the coffee argument

 

I never put anything less than 93 Octane gas on both of my MINIs (MC and MCS) unless there is not Premium gas available at the station I happen to be at.

I don't understand why people get so cheap with a new $20K + auto. Then they wonder why the car gives them trouble years down the road.

 

Forget about the price and worry about the engine.
I don't remember all the mechanics involved, I'm sure one of the resident motorheads will chime in, but these cars recommend high octane because of the higher compression of the engine. If the gas is too low an octane it's possible to get detonation and cream your engine. I know there are safetys involved to retard the timing to prevent detonation, but I wouldn't chance it.

 

I've never run regular, but I did do midgrade once... once, that is. I definately noticed a loss of power and responsiveness. I also think that economy dropped by 1-2 MPG.

I can also tell the difference (in engine responsiveness) between cheaper fuels and 'first tier' fuels like Chevron/Shell with Techron.

 

The MINI's engine computer has an "Anti-knock" fail safe feature. You can run 87 or 89 gas in the MINI and not hurt the engine right then and there, but then again you are increasing the wear of the powerplant, lowering its performance and quite possible spending more at the pump (False economy)

I believe the MCS engine is low compression, hence the requirement of at least 91 octane fuel.

But if you ever have to pour in 87 or 89 octane gas, the car will run fine as the computer will adjust the spark to prevent knocking. But don't turn it into a habit.

 

It's false economy. The sensors will adjust the timing to prevent detonation so the effort the engine puts out to maintain the level of performance you average will go up. So you save up front and repay when you fill up again.

 

You beat me to it.....my thyoughts exactly.....well not exactly........I would have ended the statement like this .........I can drink $120 worth of beer in a night!

 

I was at a gas pump once and, as usual, a guy came up and admired my MCS LY/B. While talking to him, I grabbed the Reg Unleaded pump and filled her up. Didn't notice until he left and I put the nozzle back in the pump. Definitely noticed the lack of zip and a little rough idling. As soon as I had used half a tank, I filled up with Premium to try and get the Octane up as soon as possible. I noticed a difference right away.

Lesson learned, will pay more attention in the future.

 

I've used mid-grade several times. Didn't notice any difference. In my opinion it's not nearly as critical to use premium as most people seem to think it is........but I do.

 

No experience with Mini (and never will) but I just sold my Infiniti and my girlfrind filled it once with regular, and my buddy did it once when he borrowed it. Both times It would not start a day later!

As pointed out earlier the grand total difference is about $10 a month........that's one beer a week!

 

I think a lot of it would depend on the quality of the gasoline, how much gas was left in the tank before you re-filled it, etcetera. I wouldn't expect a big difference going from 91 octane to 89, but you might if you went from 93 to 87.

I've also had people tell me that even with 91 octane gas, the ignition timing is still being retarded somewhat. I don't know if that's true, and I don't know if there's a way to "peek into the computer's head" and find out for certain, but some of the local MINI owners have tried 100-octane unleaded for trackdays and felt a noticeable difference compared to the 91- or 93-octane gas that they use regularly. No first-hand experience, but I'll probably try it once sometime when I can borrow a G-analyst or similar instrument and get some empirical evidence one way or the other.

Scott

 

Exactly.

For the most part, I only have to fill my car up once a week, and at this time I only have to put in about 10 gallons to "fill 'er up". Here right now, regular is 2.25/gal, premium is 2.45. At ten gallons, the total savings difference is $2.00.

Before I bought my MINI, I drove a Subaru SVX, which also calls for premium. On a few occasions when I had no choice, I had to fill up with regular. The car would stall, have a terrible idle, and sometimes I would have a horrible time trying to get it started. It would also have terrible fuel consumption (3-5 mpg LESS than when running premium). I know that this is anecdotal, but with that car it clearly cost more in fuel to put the "cheap" gas in than run proper premium fuel per Subaru's recommendations. The engineers who design these things know what they are doing! I trusted Subaru, and that car ran like a dream until some guy fell alseep during rush hour and crashed into me. I currently trust BMW/MINI, and my MCS has been trouble free for almost 33k miles

 

Had the same experience as DEJAVU mentioned above. Didn't pay attention to what I was doing and out of habit just put in medium grade.(My 99 VW NB ran just fine on medium grade). Notice a big difference both in the MPG I got and performance. The car still ran, no knocking, but just not as well, more sluggish and my mileage wasn't as good.
Our other car is a Saab Viggen Turbo, so putting Premium Gas for me wasn't as big of shocker as it might be for others here - the difference as Mark C. points out, at least for me, in performance and MPG is worth it!

 

Hey everyone,

I have really bad experiences putting regular fuel in my car. When I just bought my Corvette, the prior owner put regular in it. There were some bad cases of the car bogging and quiting in traffic. I felt really embarassed, and vowed to never put crappy fuel in a not crappy car.

medic

 

My friend has put Premium in a small FORD truck since the beginning...the truck is over 20 years old and runs like a dream!

YES, your MINI deserves Premium!!!!

 

Haha...best post of the thread.

 

Thank you, thank you!

 

I have two words: absoluely necessary,
You will really really feel the difference if you dont put premium gas into your MINI, especially your MCS