When you consider the compression ratio of the Gen2 engines, you'd better be using premium! The MC's is 11.0:1 and the MCS is 10.5:1. The tech manual says 91-98 octane. That's all that ever goes in my MCS. Bent rods and burned valves are zero fun!

 

+1

 

*shrug* You can only get 91 octane E10 shell in this part of the country it seems... although I did get lost one day and saw an E85 station "somewhere" on the south shore of Boston...

 

92-93, SHELL, been averaging $3.01-$3.03 where i get it

 

What Tech Manual did you see this in. The Tech Manuals at my dealer state that 87.

NO the dealer is not mistaken and my dealer also recommends using 87 if it works in your car.

And where do you get this "The owners manual says to use premium" when in fact the maunal states "Super Premium gasoline AKI/91 is recommended. However you may use gasoline with less AKI. The Minimum AKI rating is 87."
Just look at the picture of the manual page here. https://www.northamericanmotoring.co...//ppuser/51347

i can not post this picture to the thread for some reason.

 

The tech manual I referred to is the dealers Technical Service and Vehicle Data manual published by BMW c.2008. My dealer gave me a print out of the pages I asked for when I purchased the car. BTW, my owners manual and various stickers on the car all say 91 octane.

 

I would like to see copies of all of these as the pages from the dealer Tech Manual i have seen do not say what you are saying.

Also I have posted a picture of my owners manual and it only "RECOMMENDS" does not say you MUST use 91 and it very specifically states using 87 is okay as seen below.

 

Use whatever fuel you want. I know what's going in my Calif. MINI.

 

So you can not show us the documents that you are quoting? How are we to believe what you are saying when all the documents I have seen and one I have posted say that 87 is okay to use but we recommend 91 anyway.

Bcause what really distrubs me is all the people (not you specifically) saying things like

You will void your warranty if you use anything less than 91 octane.

You must use 91 or you will have problems

Your sales rep is mistaken. (in response to another comment about a dealer saying it is okay to use 87 octane)

This is all BS.

If there is some "proof" to the above claims then we all should be made aware of this otherwise this subject needs to be dropped.

 

The following is the info published in the 2007 MINI Owner's Manual:

Required fuel
Super Premium gasoline/AKI 91 This gasoline is highly recommended. However, you may also use gasoline with less AKI. The minimum AKI Rating is 87. If you use gasoline with this minimum AKI Rating, the engine may produce knocking sounds when starting at high outside temperatures. This
has no effect on the engine life. Do not use any gasoline below the specified minimum fuel grade. Otherwise the engine could be damaged.

Use high-quality brands
Field experience has indicated significant differences in fuel quality: volatility, composition, additives, etc., among gasolines offered for sale
in the United States and Canada. Fuels containing up to and including 10% ethanol or other oxygenates with up to 2.8% oxygen by weight, that is, 15% MTBE or 3% methanol plus an equivalent amount of co-solvent, will not void the applicable warranties with respect to defects in materials or workmanship. The use of poor-quality fuels may result in drivability, starting and stalling problems especially under certain environmental conditions.

IMHO the bottom line is, feed the beast premium, top tier fuels and the car will run the best and there will be less hassles with the dealer if there is a fuel related problem.

 

I've seen all this stuff many times before. I personally use 91 (highest available to me). Allowing for mileage, a 14 gallon tank of 87 currently costs me about $40. A tank of 91 costs me about $42.40. I drive about 420 miles on a tank. I've used about 100 tanks of gas in my car since I bought it 40 months ago. So the premium has cost me an extra $240. 6 bucks a month. 20 cents a day. I lose that much change in the couch cushions. Big freaking deal.

 

Premium: 93 octane here in TX.

 

Well, where I live (in Canada), premium fuel (91) costs minimum around 10 cents per liter more than regular (87). A 50 liter fillup of 91 costs a minimum $5.00 more. I've seen 91 as much as 15 cents more per liter - - that would be $7.50 per fillup. NOT an insignificant amount, to me.

What is insignificant is the difference in performance and economy between 87 and 91 octane. I've done several "seat of the pants" tests where I've used 91 (or Sunoco Ultra 94 in some cases) for 3 fills in a row, then used 87 for the next 3 fills. I have never noticed any performance or mileage differences at all in my day-to-day driving. No "knocking", difficult starting, more or less apparent engine power - - nothing.

I still fill up with premium from time to time, but most of the time it's regular (87) for me. Why pay more for something with no apparent benefit?


ps - - I have an '08 JustaCooper, totally stock except for the tires - General Altimax HP 205-55-16's (replaced the Conti runflats ~ 2 months ago).
__________________________________________________ ________

 

The way I interpret the words in the manual is that 87 is the bare minimum you can use without voiding the warranty, but they are not recommending it. So, if you accidentally put 87 in the car, don't worry about it.

When they say they "AKI 91..is highly recommended" I take that to mean that is what you are supposed to be running if at all possible. The lower AKI gas allowance is meant for situations where you cannot get 91.

The MINI's computer will alter timing for a lower AKI, but that is not an optimum situation for the engine.

 

Just throwin this out there for my Gen1 from fuel door:

 

Been using regular 87 for 23,000 miles. No issues.

Seafoam every oil change seems to do the trick.

 

Using Seafoam every oil change seems like overkill. It might even damage the sensors and create all new problems.

 

Never had a single problem on the R56 or the R53.

 

Since 2003, all my cars get 87. Costco if possible.

2003 E320 (Premium recommended)
2003 Honda Accord V6 (87 recommended)
2003 Lexus ES300 (87 recommended)
2010 MCS (Premium recommended)

 

Just make sure you don't put in E85!

http://www.examiner.com/x-696-Auto-Examiner~y2010m5d16-Costco-gas-allegedly-ruined-engines

 

e85 all the way.

 

The gas application breakout for the S, JCW, and non-S is provided in this manual.

 

The MINI owner's manual is a sick joke in places and that's one of them. It says 91 octane "highly recommended" for the S and JCW. However, inside the gas cap of the S and JCW it says "91 octane minimum"! Also, the first time I read the part about "knocking" having no effect on engine life I wondered what planet these guys were on! For any high compression turbo/supercharged engine, I'm going to use the highest octane fuel I can find. Don't like engine rebuilds!

 

There's a Union 76 about 40 miles from where I live that has 100 octane fuel. Does anyone know of a good blending chart that will show how much 100 octane to mix with say 91 stuff to bring it up to say 93-94? Also, if I already have a tune do you think it would benefit from the higher octane or would it need to be retuned to take advantage? This is mostly just out of curiosity as I know there are some really smart people on this site just dying to geek out about this.

 

Ha, I should have just asked the "Goog" in the first place. Just found this.