People allways get freaked out by paying more for premium gasoline. They look at the price and think about the $0.20 per gallon or so extra they are paying and it bothers them. However if you do the math it really does'nt make that much diffirence. As an example if you drive 15,000 miles per year and your MINI gets an average of 28 miles per gallon you would use around 535 gallons of gas. If you had to pay an extra $0.20 per gallon this would cost you around $107 per year additional for premium. Is it worth $9 per month to have your MINI perform as it was designed to?

People will drive 20 miles to save a nickle on a gallon, go figure. Put the fuel the car was made for in the tank and have fun.


Fatbob
EB S

 

I don't know much about gasonline. Am I to understand, that, the additives are worse for your engine, and are only there for emissions purposes? Is it true to that only premium fuels have additives? And finally, it may not be penny wise but what about lower octane fuels with octane boosters, will this satisfy the octane requirements with out the oring eating additives. Here in Alaska most fuel stations have premium ratings of 89-92 octane, the are oxygenated with ethenol, depending on were you are. I live in Anchorage and the octane rating is usually 92, but if I drive 50 miles north that rating drops to 90, and if I go south the rating goes down to 89.

 

>>Like I said, Its up to you. I'll take the extra Latte thank you, and drive my perfectly tuned, non-detonating cars as well. I also own a Mercedes SUV that has a lower compression engine that supposedly needs high octane. The service manager told me that the reason they can't recommend lowert octane in the US is because the smog tests are passed using the higher octane, which does burn slightly cleaner. >>

Well, it's settled then. $1.50 a week more for less polution? No problem! I've got a lot of change to get rid of anyhows.

 

For those of you who care....

I conducted my own gasoline experiment (highly un-scientific).

I normally run premium gas in my cooper S. Typically I find myself putting in 19 octane using the Ron/Mon devide by 2 formula (it says this on the pump).

A few weeks back I and filled up at a local gas station that sell "racing" gas straight from the pump. It was 100 octane using the Ron/Mon devide by two method. It was 4.25 a gallon (ouch), but I had to find out for myself.

I was interested in seeing if there was any performance or Gas Mileage improvement.

There was NO gas mileage improvement, and an inperceivable performance change. Summary - it was a waste of time and money.

I have a tendancy to believe those who say to use an octane that prevents the "knocking". Knocking as I understand it is the fuel igniting before the spark plug fires, because of compression. Octane reduces the potential for fuel to ignite under pressure. The higher the compression in the cylinder, the higher the octane needed to prevent premature combustion.

My two cents.

 

OOOOppss...hehehe..

that was supposed to ready 91 octane...not 19.

 

"There was NO gas mileage improvement, and an inperceivable performance change. Summary - it was a waste of time and money."
That's because the engine was designed for minimum 91 octane fuel. Try the opposite experiment: run 87 and compare gas mileage and subjective performance. On my 79 Saab trubo, my mileage was enough better on premium fuel that it was actually cheaper to use it as opposed to regular. The performance was markedly improved as well.

 

"A few weeks back I and filled up at a local gas station that sell "racing" gas straight from the pump. It was 100 octane using the Ron/Mon devide by two method. It was 4.25 a gallon (ouch), but I had to find out for myself."

I believe, and I haven't used it since '92, that racing fuels are leaded. Someone correct me if I am wrong. All the cars I have ever raced have had no emissions equipment and that was why we used race fuel. I may be wrong.....'92 seems like a loooong time ago

_________________
2Minis

 

>I believe, and I haven't used it since '92, that racing fuels are leaded.
>Someone correct me if I am wrong. All the cars I have ever raced have
>had no emissions equipment and that was why we used race fuel. I may
>be wrong.....'92 seems like a loooong time ago :smile:

Actually, typically at racetracks you can purchase leaded or unleaded 'race fuel'. In fact, Formula 1 racers use a specially forulated unleaded fuel. (F1 Reference: Formula One Cars)

There are several companies out there that produce and distribute both leaded and unleaded racing fuels - example: VP Racing makes 102.3 octane (R+M/2) unleaded.

Unless you're running a modified ECU fuel/ignition map I can't understand how paying $4+/gallon helps improve your performance. For BMW and Audi cars I'm familiar with a couple aftermarket tuners that you can re-map your fuel/ignition and it will actually require minimum 100 octane (R+M/2) fuel.

Even Chevron, Shell, Amaco, etc. have produced (and some still do produce) specialty high octane leaded and unleaded fuels for track consumption.

-dq

 

>>So. Techron is not just a detergent? It is an octane additive as well?
>>I thought it was just napthalene(?sp) related to common cleaning solution.

Naphthalene is what moth ***** are made from. OBVIOUSLY all we need to do is buy 87 octane gas, keep a bag of moth ***** in the boot, and toss a handful in every time we gas up! That's got to be more cost effective, and will keep moths from devouring that nice cloth upholstery.

 

Just to clear something up (and if this is somewhere in the 3 pages of posts--sorry for the repeat)

All octane does is prevent detonation (increases resistance to detonation.) It does not provide more power, nor necessarily burn cleaner, etc.

You have to get into oxygenated race fuels to actually run fuel that has more power/oz.

If your car has high comp. pistons, advanced timing, or is just prone to detonation due to heat, you need higher octane. In other words--if your car is manufactured to make use of it, you should run it.

I don't know what the compression in the mini gets to at full boost, but from toying with bikes the number is somewhere between 11:1 to 12:1 compression ratio before you'll start to ping on regular (87 octane) gas.

Now, some cars are equipped with knock sensors, and will actually advance the timing to take advantage of high octane gas, and actually get more performance. Conversely I think they retard timing if they detect knocking to play it safe.

So maybe the Mini needs it because under boost the compression is high enough to warrant it. As for premium being cleaner, which gas do you think sits in those tanks underground longer? Regular or premium :smile:

Finally (off the subject a little bit) if your car is designed to run on good old 87 (in the USA--lowest grade), running a higher octane will not help, and could actually hurt. You'll get less power and more heat because it burns a little slower (remember--resists detonation.)

Well, there you go. Everything I've learned about gas in the last few years. (I won't talk about detergents & stuff--know nothing about them!)

Jeff in ATL

 

From BMW's own marketing text on the MINI (I found this at europeancarweb.com):

"As supercharged power units are prone to engine knock, the compression has been reduced from 10.6:1 on the MINI Cooper to 8.3:1 [on the S]. Morever, the knock sensor of the active knock control constantly monitors the combustion process. Active knowck control allows the engine to run on unleaded fuel with an octane rating of between 91 and 98. This, in turn, allows the same engine set-up in all markets the world over, regardless of the fuel grades and qualities available."

Of course, you could end up with supposed 91 octane gas which was of such low quality that it actually was BELOW 91 (and that seems to be the point of most of the 3 pages of posts above this)...but of course, that would never happen from BMW's perspective

 

I bought a used 2012 Mini Cooper with sport package from a local dealer. The car is in good shape and ran very well when I tested it and the week following me purchasing it. I wasn't told to put premium gas in it and was putting low octane regular gas in it ever since.

I began noticing some hesitation on take off but didn't think anything of it. Yesterday, approximately a month of using low grade fuel, I was driving down the interstate and tried to pass a vehicle when my car suddenly lurched and lost power. It didn't stop running but simply lost it's get up and go.

The engine symbol in yellow came on and I thought something very bad happened. When I could pull off the road I did and shut the car off and called the dealership. Of course there was no one there that could talk to me and I was told to make an appointment on monday.

After that I took out the owners manual and found that high octane, preferably bp detergent gasoline, should be used in my model.

I did go out and buy a can of octane boost the following day and it seems to have helped. What I am concerned about is that I may have done considerable damage to my engine since I've been running low grade fuel in it for a month.

I did notice that my tail pipe has a small amount of black soot coating it which seems bad. Does anyone know if I've done permanent harm to my vehicle? Please let me know asap.

 

Just use better gas going forward, you should be fine.

 

the CEL is probably a misfire code. read that using lowest octane 87 is okay only if you're not driving spiritedly with high rpm. so, it's best to use min 89 as shown on the label of the gas cap.

 

First off....what you read is for gen1 cars, aka 2002-2006 hardtops, and 2006-2008 cabrio...aka r50/52/53...
The answered are diffent for gen1 cars than for gen2 and gen3 cars...different motors....
This thread is from 2002....so you win an award for digging it up...
Short answer is gen1cars REQUIRED premium....valves would get burnt if it is not used.
Gen2 and 3 are recommended but not required.

 

which premium, 91 or 93 ? I can get both depending on the station

 

Gen 1 R53, premium (91+) is the only gas you can use.

 

If the CEL returns, you may have a failed or failing knock sensor. Talk to MINI owners in your area about the best INDEPENDENT MINI shop for service, NOT the dealership.
Besides top octane from now on, use only fuel from the list of Top Tier stations.
http://www.toptiergas.com/retailers/

 

Jealous you can get 93... only 91 available here in CA

It depends on your mods, but if you have a pulley, especially greater than 15%, and it gets hot in your area, I would run 93.

 

I can tell a difference in performance from 89 to 91, but no difference from 91 to 93. Usually get 91, but sometimes at SAM'S or COSTCO I'll buy 93; seems the same as 91 in performance and MPG.

 

Yep, 93 would be a waste with a regular Cooper, but if you have an S with mods it's something to consider.

 

have any idea what "octane" means or is or what it actually means in the sense of fuel for our cars?

Find out and you will answer your own question . . .

 

Dang, wish I'd said that. All the past discussions over this issue and you crystallized in a matter of seconds. Well done.