I pulled into the gas station for a fill up and pressed the 93 button but for some reason it dispensed 87. I put a bottle of "104 octane boost" in the tank. Will this or do I need to take more drastic measures?

 

One tank of lower octane will not hurt your MINI. Its computer will adjust for the lower octane, but the MINI Owner's Manual does state that Premium fuel is the proper gas, so.....DON'T EVER LET IT HAPPEN, AGAIN!


Clover

 

Mechanically, you have nothing to worry about...

However, I believe the official MINI punishment is to wash, claybar your ENTIRE MINI and then apply a minimum of 3 coats of a premium wax.

Then hope your MINI forgives you!

 

Thanks for the input. I will not re-clay bar the car and take off my 10 coats of zaino. I guess I should just enjoy the .20 savings per gallon.

 

Although the octane booster in a can does technically increase octane, it is much too small of a volume to make any significant difference at all.

When those cans say they raise octane by 3 points, they are somewhat deceptive. 87 does not become 90, but instead becomes 87.3. In order to raise the low octane gas to the MINI reccomended 91, you would need to add about 2-3 gallons of octane booster.

These octane in a bottle products are typically either toluene, xylene, or a combination of the two.

I have had great success in the past using toluene and xylene to formulate my own home-brew race gas, but I had access to large volumes of these chemicals for free.

See this website for more info on octane boosting chemicals which I do not suggest anyone actually mess around with. The information is interesting though

http://au.geocities.com/ozbrick850/e...taneboost.html

 

I'm getting mixed messages on octane for my MCS. My MA said I must use 93. Above post says "...Mini recommended 91." Understand 93 is na in CA. Does that mean they all can expect problems? I also read an interesting discussion on Edmunds.com from a Canadian who reports experience with 87,89,91, & 93. Concludes 91 gives best milage. (see message around page 104-105). What do you say?

Hugh

 

I inadvertently filled up with regular unleaded once too. But since I refuse to use any fuel or oil additives, it was a week of painful driving before I could refill with premium!

Once back on premium, the MCS recovered nicely although it took a couple days (the wonders of adaptive software...). No need to worry.

 

Happened once to me.I ran down a 1/4 tank,topped up with 91,did it again,next 1/4 tank.I did notice that I got lower MPG with the 87.

 

Maybe the gas station has only 87 octane but those who press the premium button get to pay more per gallon.

You should have asked for a "refund" since you "hurt" your MINI (point to the premium only sign). You really will be fine though.

The Octane boost isn't going to help much by itself. Lots of moth ***** would though.

Drastic measures? Well, you can drive faster and longer for a week and drain you gas tank pronto so you can put in some premium.

I have only 92 octane for premium in my area. The premium will perform better than the 87 if you drive "like you stole it".

 

Hugh, there's another thread on NAM somewhere on this very topic... try a search on "octane". From what I recall, the consensus was that 91 is fine, but many were going for the 94 (or whatever their area offered instead of a 93).

 

strange, i noticed about 35 more miles on a 1/4 tank of gas with 93 over the 87. i was useing 87 because of the prices, but it doesnt make sense now, i get better gase mileage with he 93, so it balances out....

 

What's the scoop on using middle grade (89 Octane) instead of dealer recommended premium (91 - 93 Octane) for 2003 MCS?
I'm willing to sacrifice some performance for cost saving on gas as long as it does not cause damage or wear to engine.

 

I've merged these threads as they are close enough in content and they're both "alive" right now...

 

As a rule, on high compression or boosted engines you should use a premium gas. The heat caused by these engines cause detonation which is bad for your car... you could be blowing holes in your pistons. Yes, today's cars have knock sensors to reduce detonation, but this is usually done by retarding the timing which kills the performance of you car and the correction doesn't kick in until detonation has already been detected... by then its too late... the damage is done. This is not to say that accidentally putting in 87 will kill your car, but repeated use of low octane gas can result in a shorter life of the engine. Food for thought

 

MINI is my first car that ever required premium. It's 10 cents per gallon more than mid range here in NJ. Mini tank is 13 gal. = $1.30 per tank, x 52 weeks = $67.00 per year. For that $$$ I'll take the optimum performance (that's why I bought a mini s in the first place!) and rest easy re proper maintainance.

BTW. I got my 05MCS blk/blk/prempkg,armrest last Fri. Drove according to break-in specs (honest). Got 28 mpg ! Think I'll keep this puppy!!!

Hugh

 

In my area, we only have 87, 89 and 93. No 91 can usually be found. Lately I have gone between using 93 and 89 in my Cooper and can not tell a difference with mileage or performance after using 93 only for the first year of ownership. My M.A. actually advised me to try a lower octane when I described an intermittent stalling issue I was having with the car. After starting it cold and driving a short distance and stopping, sometimes RPM would drop or the engine would actually stall.

 

In CA we only have 91. I've filled up the MINI with 91 and have had no problems. I feel like she performs perfectly w/ the 91. Gas mileage has been on a steady climb since I got over the 5K mileage plateau as well. I did put in 89 once, yuck. Bad mistake, won't do that again.

 

It's like giving your 16yr old son a viper, and telling him to take it easy!! I have a couple of friends that have perfected a "homebrew" for their auto-x cars that are running around 12:1 or so.

 

A few years back there was a local news report about gas stations mislabeling their higher octane fuels as lower ones. Does anyone know if there are any octane test kits you can use to check whether the fuel you are dispensing is really what it claims to be?

 

From the engine white paper on the Supercharged MCS engine.

"With knock sensor control, it can be safely run any any gas World Wide, but the engine is optomized for 98 RON."

US gas is labled (ron+mon)/2 and you generally add about 3 to 4 points to figure the RON number.

The wider your throttle is open, the more important knock control / octane becomes.

This seems to me to mean that if you don't have your foot in it, octane may not make a difference.

I still have not tried anything but 93 (U.S.A.) in ours.

John

 

Hey Jeff,

I don't think I would really lean into it until it runs through the gas.

Most importantly though, what gas station did you fill up at, so I can be sure to avoid it...

 

On the return portion of my cross-country roadtrip last year, hubby would put mid-grade gas in Wanda at the half-tank reading, but only in states with 93 octane rated premium. We're used to 91 in Cali, so having the thrill of over-91 octane made us realize we could dilute it a tad with mid-grade at the half-tank point. And she ran like a champ, as usual!


Clover