Our cars recommend 91 octane for optimum performace
10-27-2010, 08:51 AM
#2
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Consumer Reports did a study on this and determined that most people throw away money by putting a higher octane in their vehicles than called for by the manufacturer. They equate the octane rating with quality and figure they're doing their engine good by using say, mid-grade instead of regular. I don't believe you achieve any increase in performance by using 93 instead of the recommended 91. You will, however, experience a degradation in performance by using anything lower than 91.
10-27-2010, 08:56 AM
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no you aren't getting a performance increase, but to comment on jayarras comments, i don't know about you, but in dallas they only have 87, 89, and 93. there is no option for 91, so i wouldn't really say we are throwing money away on purpose. besides, the extra money (what, $50?? maybe) you spend a year in gas on the difference between 91 and 93 is hardly worth bitching about.
10-27-2010, 09:31 AM
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No added performance for using higher octane than the mfg. suggestion.
All you ever need is 91 AKI ( Anti-Knocking Index) octane which is HIGHLY recommended as per your car manual. 93 octane and above is a waste.
But of course, if only 93 is available you have no choice.
http://www.imakenews.com/tituswillfo....cfm?x=b11,0,w
In the world of automobiles, it is tempting to associate higher numbers with higher quality. After all, more horsepower and more miles per gallon are a better thing, which feeds into our perception that more impressive octane ratings also equal higher performance. Gasoline companies understand this mentality and do nothing to dissuade drivers from it, labeling 87 octane gas ?Regular,? and 91 or 93 octane ?Super? in an attempt to reinforce this way of thinking. After all, since ?Super? is priced higher than ?Regular,? it?s in their best interest to convince as many people as they can that paying a bit extra means getting better quality gas.
Time and again, people will be told that high octane fuel burns cleaner or more completely, and that it will give them extra power and better fuel mileage than Regular octane gasoline because it contains more ?energy.? These blanket statements are simply not true. In fact, the octane rating for gasoline has nothing to do with the amount of power locked inside of it ? it actually relates to just how much a fuel can be compressed before igniting. The higher the number, the less likely it is to ignite under pressure.
To wrap things up: no, you won?t see a power or fuel efficiency increase by running high octane fuel in an engine that has been tuned and designed for Regular gas, nor will doing so perform any extra ?cleaning? inside the motor. On the flip side, running low octane fuel in an engine built for Premium can increase the risk of engine damage and will certainly impact that unit?s overall performance. The next time someone tries to pass these myths off on you, you can try explaining to them how octane ratings really work ? or you can just smile and nod, pay for your gas and move on.
http://www.carsales.com.au/advice/20...ar-faster-7513
If a higher octane fuel is used what happens? Well, nothing. The engine is already able to perform at its highest efficiency on the recommended fuel. The extra octane rating has no effect.
http://en.wikipedia.org/wiki/Octane_rating[/QUOTE]
A common misconception is that power output or fuel mileage can be improved by burning higher octane fuel than a particular engine was designed for. The power output of an engine depends in part on the energy density of its fuel, but similar fuels with different octane ratings have similar density. Since switching to a higher octane fuel does not add any more hydrocarbon content or oxygen, the engine cannot produce more power.
First important fact that you must accept:
All gasoline, regardless of its? octane rating, have pretty much the same amount of energy per gallon. What!!! "Sacrilege" you say? Well, actually, some higher-octane fuels have a few LESS percent energy per gallon?so as not to argue over this small point, for the sake of this discussion we will all agree that the automotive gasoline that you buy at the pump, regardless of octane rating, has the same amount of potential energy.
Second important fact that you must accept:
Octane is NOT a measure of power but of the fuels? resistance to ignition from heat. A higher-octane fuel, under identical combustion chamber conditions, will burn slower.
There is ABSOLUTELY NO BENEFIT to using a higher octane than your engine needs. The only benefit is increased profits to the oil companies that have cleverly convinced some of the public that their new "Super-Duper, Premium-High-Test, Clean-Burning, Used-By-Famous-Racing-Types-All-Around-The-World, Extra-Detergent-Laden-Keep-Your-Pipes-Clean, Extra-High-Octane" fuel is your engines? best friend.
All you ever need is 91 AKI ( Anti-Knocking Index) octane which is HIGHLY recommended as per your car manual. 93 octane and above is a waste.
But of course, if only 93 is available you have no choice.
http://www.imakenews.com/tituswillfo....cfm?x=b11,0,w
In the world of automobiles, it is tempting to associate higher numbers with higher quality. After all, more horsepower and more miles per gallon are a better thing, which feeds into our perception that more impressive octane ratings also equal higher performance. Gasoline companies understand this mentality and do nothing to dissuade drivers from it, labeling 87 octane gas ?Regular,? and 91 or 93 octane ?Super? in an attempt to reinforce this way of thinking. After all, since ?Super? is priced higher than ?Regular,? it?s in their best interest to convince as many people as they can that paying a bit extra means getting better quality gas.
Time and again, people will be told that high octane fuel burns cleaner or more completely, and that it will give them extra power and better fuel mileage than Regular octane gasoline because it contains more ?energy.? These blanket statements are simply not true. In fact, the octane rating for gasoline has nothing to do with the amount of power locked inside of it ? it actually relates to just how much a fuel can be compressed before igniting. The higher the number, the less likely it is to ignite under pressure.
To wrap things up: no, you won?t see a power or fuel efficiency increase by running high octane fuel in an engine that has been tuned and designed for Regular gas, nor will doing so perform any extra ?cleaning? inside the motor. On the flip side, running low octane fuel in an engine built for Premium can increase the risk of engine damage and will certainly impact that unit?s overall performance. The next time someone tries to pass these myths off on you, you can try explaining to them how octane ratings really work ? or you can just smile and nod, pay for your gas and move on.
http://www.carsales.com.au/advice/20...ar-faster-7513
If a higher octane fuel is used what happens? Well, nothing. The engine is already able to perform at its highest efficiency on the recommended fuel. The extra octane rating has no effect.
http://en.wikipedia.org/wiki/Octane_rating[/QUOTE]
A common misconception is that power output or fuel mileage can be improved by burning higher octane fuel than a particular engine was designed for. The power output of an engine depends in part on the energy density of its fuel, but similar fuels with different octane ratings have similar density. Since switching to a higher octane fuel does not add any more hydrocarbon content or oxygen, the engine cannot produce more power.
First important fact that you must accept:
All gasoline, regardless of its? octane rating, have pretty much the same amount of energy per gallon. What!!! "Sacrilege" you say? Well, actually, some higher-octane fuels have a few LESS percent energy per gallon?so as not to argue over this small point, for the sake of this discussion we will all agree that the automotive gasoline that you buy at the pump, regardless of octane rating, has the same amount of potential energy.
Second important fact that you must accept:
Octane is NOT a measure of power but of the fuels? resistance to ignition from heat. A higher-octane fuel, under identical combustion chamber conditions, will burn slower.
There is ABSOLUTELY NO BENEFIT to using a higher octane than your engine needs. The only benefit is increased profits to the oil companies that have cleverly convinced some of the public that their new "Super-Duper, Premium-High-Test, Clean-Burning, Used-By-Famous-Racing-Types-All-Around-The-World, Extra-Detergent-Laden-Keep-Your-Pipes-Clean, Extra-High-Octane" fuel is your engines? best friend.
10-27-2010, 10:36 AM
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My Ride: 04' 545i, Sport Package, Black, Active Xenon, ARS, Aux Input
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I may have to switch gas stations... the one I go to jumps from 89 to 93 octane... damn! 
10-27-2010, 10:39 AM
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My Ride: 08 528I Sport/Prem
So our tanks need roughly 15 gallons to fill up.
What if you do a 50/50 mix of 89/93 octane fuel.
Would that equate to 91?
A person could save a few dollars by doing that, but is it worth it? LOL
What if you do a 50/50 mix of 89/93 octane fuel.
Would that equate to 91?
A person could save a few dollars by doing that, but is it worth it? LOL
10-27-2010, 11:01 AM
#8
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no you aren't getting a performance increase, but to comment on jayarras comments, i don't know about you, but in dallas they only have 87, 89, and 93. there is no option for 91, so i wouldn't really say we are throwing money away on purpose. besides, the extra money (what, $50?? maybe) you spend a year in gas on the difference between 91 and 93 is hardly worth bitching about.
Hey, 50 bucks is 50 bucks! I won't inconvenience myself, but I'll definitely go to the places that sell it cheaper. In my area, prices will sometimes vary 15 cents from town to town. We, in Connecticut, have the 2nd highest gas tax in the nation. Currently, 93 is averaging about $3.10 a gallon.
10-27-2010, 11:30 AM
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At a couple of the Sunoco stations I use, the price difference between premium (91) and Ultra (94) is one cent ... so for the penny per gallon I save with every fill up can save to buy another Rolex or save up for a few more weeks and get another Maybach 57.
Suggestions welcome
BTW, I must be getting lots of additional horsepower and ft pounds of torque with the Ultra cuz my 530xi can blow the doors off a Prius any day
!
Suggestions welcome BTW, I must be getting lots of additional horsepower and ft pounds of torque with the Ultra cuz my 530xi can blow the doors off a Prius any day
!
10-27-2010, 11:40 AM
#10
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... I might add that NJ has some of the LOWEST gas prices in the country! I know prices are going up all over the place, but what are you paying for Ultra these days?