Big girl panties a lil small today? If I wanted to be flamed, I'd buy a Porsche.

 

I think it is more of ECU's ability to adapt the timing... that is why the Mazdas can do this. Similar to the 500 Abarth and Dodge Dart as well, i think, where the boost and timing fluctuate depending on fuel to retain the torque line. I read some where that Fiat 1.4T ECU will increase the boost spike up to 20+psi when the timing retard to compensate for the crappy fuel.

 

also, $4.30 around West Los Angeles area

 

Adding a turbo will easily raise a compression ratio to 18:1 at full boost. (9:1 comp, sea level 13 psi boost..)

Yes, an ECU can "adjust".. It will slow the car down. Adjust timing, lower boost.. It will not damage anything... But...

Um... Why did you buy an "S" again..?

 

while people do have a point with "modern" engines, i.e., hyundai genesis turbo's ecu will scale back to make less power if it detects lower octane gas, it is still always a better idea to run 93/best octane you can for a turbocharged car. also, MINI will need to actually specify that you CAN run lower octane if you are looking at that case

 

Compression ratio is only one variable. The ability to finely control the fuel mixture, ignition timing, boost pressure, valve lift, cam timing, etc. in modern direct injection engines makes it possible to run different grades of fuel without damage.

That being said, I wouldn't run anything less than premium through a new Mini... base model or an S.

 

Guy at work has a ford escape 2L ecoboost that specifies 87. When he hits the gas you feel nothing. Granted the escape weighs more than my mini hardtop but all the fun of the turbo is completely muted. I suppose with a name like ecoboost you see where the priorities were. I also read an article saying the ford ecoboost engines aren't delivering the better fuel economy that is to be expected from a smaller, but efficient, turbo charged engine. He gets 24mpg city and I get 26mpg, same daily commute. Apples and oranges I know but food for thought.

 

Interesting how far behind Mazda most manufacturers are. They are presently working on a 18.5:1 compression engine. they have perfected direct injection.
I personally can't help but think that all this energy put into an old engine design is a complete waste of time. They could so easily invent something better.
I'm working on a compressed air scooter with my son right now. The French with Tada motors in India are working on a compressed air car....
Get out those bike pumps...!

 

I don't believe that Mazda is behind most manufacturers but rather choosing to expand the engine technology in a different direction and not using turbochargers, with the inherent complexities and problems, producing increases in fuel efficiency and torque. I applaud Mazda for going a different route. My only question would be long term reliability.

Edit: misread your post . I blame old eyes and small print on iPad. My bad.

 

If your re-read that, GregoryK actually says everyone else is behind Mazda...

 

No one has mentioned altitude as a factor.....keep in mind that the higher you live, the less you need the higher octanes. I live West of Denver at 9000ft and never drive lower than 5000ft. This means you can run with lower octanes. Having said that, I always get the "good stuff" which in our area is 91. no one seems to carry 93.

 

My bad, I misread his post.

 

Funny, Mazda hasn't won an International Engine of the Year award since 2003.

 

And Mini won.......?

 

According to the MINI website they won the 2011
ENGINE TECHNOLOGY INTERNATIONAL MAGAZINE

INTERNATIONAL ENGINE OF THE YEAR

MINI Cooper S


-which of course we all read diligently.

 

Is it sponsored by BMW?

 

I know what the manual says, and I know what I have experienced. In "normal" driving, my MCS runs fine on regular, and gets the same mpg as on premium, as close as I can tell. The same applies to my C7 Corvette. If I am going to do "spirited" driving, I use premium in both.

I have a question, though. Why should these MINI's need premium at all? At 189 hp, MCS engine has about the mildest state of tune of any current 2.0 turbo now sold, and many, or most of them recommend regular, even though they make more power. Does BMW have bad head designs, making them more ping-prone than, say, the 240 hp Ford 2.0 turbo that recommends regular?

 

 

For the non-JCW models, MINI says 89-octane minimum and 91-octane recommended. Why would you buy a car that stipulates this if you aren't prepared to then put at least 89-octane in the tank? If you want to fill up on 87-octane, buy a car that specifically says it's OK to put 87-octane in the tank. We're talking a couple bucks per tank here (or less, depending on where you live), not thousands of dollars on the regular. Do you also cheap out on oil and use non-synthetic, even though MINI says to use synthetic? Maybe you ignore the brake sensor warning, too, because you know better when the brakes need replacing? This is a tired debate that's been around for ages with all European brands because they have typically been the brands that specify something other than 87-octane gas. Armchair and internet engineers alike recount their tales of "well my car runs fine on regular and I don't notice any differences," and "I have a car that costs $XXX,XXX and it runs fine on regular," and think that somehow they've outdone the powertrain engineers who put the "meaningless" premium fuel requirement in place. What I've learned, however, is that there is no convincing anyone to change what they've already convinced themselves of. So everyone here who believes you should follow MINI's recommendations for octane rating? Give up and move on before the debate turns hostile (and these threads always seem to, no matter the car manufacturer). OK, rant over!

 

Well said!! (I'll leave your full quote on my reply just in case someone missed your point.)

 

I use premium, but post#42 is asking for a technical answer rather than the manual says so answer. I don't know what it is but it is a good question.

 

I use synthetic oil in my MINI, and my Corvette. For years, though, it has seemed that BMW (and Mercedes-Benz) say to use premium gas in cars that shouldn't, and probably don't need it. Is it a placebo thing to make certain people feel good about spending an extra 20% on gas? FWIW, I use "top tier" gas, knowing about the valve carbon problems with some direct injection engines.

Again, from my original post, does anyone know any good reason WHY a mildly tuned, 189 hp BMW 2.0 turbo should need premium, when a 252 hp 2.0 turbo in a Honda Accord does not? Oh, and no, I don't ignore brake sensor warnings.

 

Regarding valve carbon, the gas doesn't wash over the valves on direct injection engines, so not sure what you're trying to do there.

The mini has high compression, 11:1 or something like that, compared to the accord 9.8:1, runs a lean air/fuel mixture even under boost, and high water temperatures. All probably for emissions and fuel economy. If you get a tune, even the 1.6L prince engines can make ~230 hp, get mid 20's city mpg using an S turbo but still using at least 91 octane.

If you run 87 I'm sure the computer will compensate for it, but realize that knocking occurs first, then timing is retarded. So the "damage" has already been done, so to speak.

 

The "top tier" consortium, of which BMW is a part, indicate that "top tier" gas helps re. valve carbon. No, I don't have proof.

If the Honda engine is lower compression than the MINI S engine, it is running much more boost to produce a third more power from the same displacement. Running more boost would also create conditions where pinging might occur. Again, what is BMW doing wrong, if the mildly tuned MINI S engine, in any way, really needs premium gas? I'm curious.

 

Buy the Porsche.