Hi:

I'd use 93 or better. Twelve years ago I lived in Finland and the lowest octane I recall seeing was 93. Most people who were concerned about quality and performance used the 98. They may have had 99, I don't recall exactly, but it did make even a 1980's Skoda run like the wind.

Peace!

 

I only run 94 octane in my cooper, I figger cheap price for the extra performance.

 

94 OCTANE What brand has 94????

 

Sunoco 94. Sunoco sells higher octane performance including racing fuels. I wish there was one in Houston, I have not found one yet.

 

+1! Recently saw a reputable auto shop owner/manager talking about this issue. Remember, this is the guy who will make the money off you mistreating your baby! He said running a lower octane for a very short period (emergency etc) is no big deal, but long term you're going to mess up your engine. He was speaking about cars in general, not a Mini specifically. He spoke about the timing change and how it's not good for an engine long term.
IF you can't afford the extra couple of bucks, you can't afford the car. And the car sure can't afford you.

 

running too low an octane over time causes carbon deposits on your valves.
Likewise running too high an octane puts carbon deposits on your valves.
Use what the manual says and you'll be OK.
run whatever gas you want. It's your mini. Maybe it lasts 200,000 miles. Maybe it needs to be taken apart and repaired at 60,000 miles.
I spend the extra $2.00 at the pump every fillup.

 

http://auto.howstuffworks.com/question90.htm

Even if you just read the first two or three paragraphs, it might help you make a decision

 

Seancusmc the link you just posted is great. I wonder if part of that article could be posted as sitcky so that NAM would no longer allow new threads on this subject.

It's pretty clear how the engine works, and how the math doesn't really add up to much of a saving. Everyone likes to save $, but when looking at a whole year worth timeframe a total of $80/$100/$200 per yr saving doesn't break anybodie's budget..especially after spending 20k/25k and sometimes 30k for a loaded MINI.

I am actually traking my Cooper S on the boat (going to Panama) and have been researching lots of things like gasoline requirements, maintenance, common issues with R53s, etc..

Thanks again for posintg the link to that article

 

Hi All,

I adopted my Mini from a private owner and never asked about the fuel etc. Well, for a while I ran mine on 87 and let me tell you, there IS a difference. I don't know if it's noticeable with a stock exhaust but the previous owner added a "Bosch" (can't go out and read my tailpipes right now, pouring rain) and the engine noise and exhaust noise more than doubled. I nearly went deaf and had no idea why. That and my SES is now glowing nice 'n' brightly. I went to the same place selling 87 and put 92 octane (looking for higher still) and added half a can of octane booster. I thought I forgot to start the car the noise was so much lower. Obviously I'm exagerating the truth about the noise but it truly made a difference. I won't EVEN go into the power difference it made in my 2002 Mini Cooper S. My Mini still sounds MEAN but it doesn't sound like it needs a new exhaust. Just my two cents worth in the fuel debate.

Oh, BTW, premium only ran me about $1-$2 more per half tank compared to the "cheap stuff" and my mileage is steadily increasing as the rest of the 87 burns off.

Now if I can just get rid of the P2097 code without having to break the bank for it.

 

If you're talking about the exhaust I think you mean "Borla"

I wish too, I run my MCS on 93 octane Shell, Exxon, Chevron, in that order. I don't fill up on anything else... however, I drove my mother's car a few weeks back, and the manual says to use only 89 octane.
Manufacturers tune their engines to a specific octane, and usually slightly higher is better than slightly lower, but following their instructions are best.


I was thinking about filling up at small airstrips (there's one a few min form my house) since they have 100 octane (I've heard they have different additives in their fuel that would be harmful for car engines, but I have to check, but my friend I'm about to talk about--> assured me they don't) i talked about this with a friend of mine who used was a professional drag racer and he explained to me about octane ratings and what-not. he said 100 octane was probably too much for the car, but wouldn't "hurt" it, just leave deposits like someone mentioned earlier in this thread. He recommended using an octane booster from a well know brand i.e. Lucas, and see how the car responded to the change, and go from there.
note: I'm not using the stock ignition-coil, wires, or plugs

 

Just make sure the high octane gas is unleaded or your converters will be toast!

 

Yep, you got it on the first try. If you can't tell I also have a Dodge Dakota (wifey's) and a Chrysler Pacifica so high performance stuff isn't on my list of normal things to know.

I'm also not used to needing higher octane stuff so I've got the SES nice 'n bright right now. Hoping to make it to a Mini event this sunday. Spoke to some folks showing up and they're gonna help me clear the (hopefully gas related) codes. I've been using 92 octane since I read some of the posts here and put some booster in it too. If used the booster for two refills of half a tank each so I hope the 87 (sorry my little MINI) has gotten cleaned from my tank. At only about a $2.00 increase for a half tank refill I think I'll stick with the "good stuff."

 

yea, I was planning on calling soon to find out what they had. I'm not in a rush b/c my MINI is currently out of service. sad story involving an inconspicuous pot-hole leading to a dented shock... don't ask me how. It put some major positive camber on that wheel and and made a horrible noise, Cross coil-overs are being shipped out today
speaking of leaded fuel, the drag racer i was talking to said leaded gas was better for engines (ON ENGINES THAT WERE BUILT FOR IT) and that they ran better, I was a bit surprised, but he explained why and it made sense

 

Mini chili,

This is OT but looking at the pics in your posts, can you drive your Mini between the front and rear wheels of the truck in there. Bet that's an interesting view if you can...

 

Sad news...
I checked the fuel at the local airstrip... 100LL... "Low Lead"
all the more reason to just get rid of my cats, haha

 

There are also other additives besides lead that would be harmful to your engine. Do not use aviation gas at all.

 

I figured
I'll keep trying to think outside the box

 

jet fuel looks and smells different than what we use. it pretty oily actually.

 

Also, aviation gas is meant to be used at altitude, where the oxygen content of the air is *much* lower. As such, it's not suitable for on-the-ground use, unless you completely re-vamp your fuel system to work with it.

That's for 100LL - true *jet* fuel (Jet-A, Jet-A1, JP-5, JP-8, etcetera) are basically kerosene, so you really don't want to use those in your car.

 

OK, so my manual says 91oct and so does my gas cap... but let me run something by you people.... the other day my dealer advised me to use 89 oct in the winter time in order to keep my MCS running properly... if i use 91 oct the car runs rough, and stalls in really cold weather... what do you all think?

 

Here's a clue...they don't sell 83 or 89 in the UK (or most of Europe). So...they (the Europeans) are not going to design an engine to run on lower octanes. They have one grade usually...what we call Premium (usually 94). BP now has Super Premium at 102.

 

100LL (Low Lead) commonly referred to as Avgas is absolutely not suitable for our MCS's (or any car for that matter). I run a Rotax 100hp four stroke engine in my home built aircraft and this engine can run on both Mogas (preferably unleaded and highest octane rating), no cats or Avgas. Out of interest the overhaul frequency on aircraft engines is expressed in hours. If Avgas is used the TBO (Time Between Overhaul) hours drops from 1500 to 1200. The lead leads to deposits on the valves and stem seals. Just some useless info. It smells nice and has a nice green/blue colour though....

 

When comparing US to Europe you need to realize that 91-92 RON in Europe equals 87 AKI in US: I've been running my MCS on 87 w/o any problems or mpg loss; Come summer I'll run 91 AKI

 

I can't believe that after all these years this is still an issue.

 

Was wondering if anyone knows what the reason could be that my mini is hesitating to get up to speed like a put put, its a standard 05 mini s please help