Premium Gas or Unleaded for -04 330ci-

CONSIDER
The original question is, what's better premium or unleaded? Premium IS unleaded. The question is bogus on a good day.

Originally Posted by jdstrickland

CONSIDER
The original question is, what's better premium or unleaded? Premium IS unleaded. The question is bogus on a good day.

dear "i write complaint letters to game shows guy,"

I hear 87 referred to as "regular" and "unleaded" and "regular unleaded" interchangably. All automobile gas starts off as what's referred to as "unleaded base stock." They have to put things in it to add more octane rating. They actually will only produce 2 grades for a 3 grade pump, the middle grade is mixed on the fly at the pump proportionately.



Sincerely,
"internet-forum a-hole guy" lol

Originally Posted by blksab65

Is it safe to maybe add octaine to our cars? If so what would you add to do so. You can get more power/ better gas (if you drive like a old man) am i correct?

This is extremely debatable. Without the ability to try to program your ignition/timing to take advantage of a higher octane fuel I don't know what good a higher octane than recommended would do. There are many vehicles out there that are factory calibrated to run on 87 that you can have programmed to run on 91/93 and make a couple more HP. I owned such a car and did before and after testing at the dragstrip and there was a statistical difference. That difference cost me $400 one time, and however many bucks more for every future tank of gas. However, very rarely on the street is my right foot floored for about 14 straight seconds (try it!) , trade off - dunno. And no modern BMW is factory calibrated to run on 87. . .

A tiny excerpt from a sort of interesting article where they had a hot rod engine they were trying different octane gasolines with (including the use of octane boosters) but they were also manually setting pushing the ignition advance for each dyno run, something no "off the shelf" car can do.

Wusz [76 Chemist] said, "An engine does not know what the octane rating of the fuel is, unless it is too low"; note that we made less power by adding booster to 91-octane fuel.

I think that relying on the kind of info above is important because any psychologist will tell you if you pay for something to put in your gas tank - your brain will feel a difference. Same if you were sprinkling magic concentration juice into your coffee every day (ps - if you know where I can score some of this let me know).

Also there is a ton of anecdotal evidence that octane booster supplements have detrimental effects when used regularly, or when sitting in a gas tank for longer periods. Anecdotal so I'm not going to cite it, but it's out there for the googling.

Bobistheoilguy.com has good info & discussions on this in it's forums.

If your intention is to "clean out" your fuel system/injectors, etc., with a pour in type product - even this is hotly contested. Personally I try to walk a fine line between "maybe it does help, let's try some judicious use - who knows" and "not putting in so much that it has detrimental effects."

I like Seafoam products, in my "experiments" (used in the loosest sense of the word, I usually run a .06 BAC through all these ) I have 4 lawn/garden products that all use the exact same 4-cycle engine, it's a 160cc model GC-160 engine. It has given me a chance to put similar hours on multiple engines and do Seafoam in one of them, and then crack them open at some point and examine the valves and combustion chamber for deposits and crud (it takes maybe 45min and $2 worth of liquid gasket to do this per engine). Long story short, on my little Honda engines it has a mild but noticeable effect.

So on my cars I do this once every 25k miles: Seafoam intake cleaner, 1/2 bottle regular Seafoam in the oil (right before an oil change) and 1/2 bottle in a full gas tank. When I'm done with the gas in that tank, I change the oil. It might be money completely down the drain, but it's not so much that will kill anything.

If you wanted to do your own experiments and see how much HP you could extract out of your lawn boy, the main ingredients in most octane boosters are Toulene and Xylene. You can buy pretty pure versions of them at a hardware store in the paint section (with all the other great smelling stuff).

Just my $0.02. . .to each his own.

Ffs its 3 dollars a tank difference stop being cheap.

Sent from my HTC EVO 3D using Bimmer App

Originally Posted by 325inthe510

Ffs its 3 dollars a tank difference stop being cheap.

Sent from my HTC EVO 3D using Bimmer App

it's $4.80 a tank difference here for a 16 gallon fill-up. Which is $38.40 a month, or $499.20 a year.

Toss the extra 80 cents in for those times where you squeeze it just a hair more to get an even number and you're looking at $500 per year. Which could be ten tanks of gas.

Originally Posted by NOVAbimmer

it's $4.80 a tank difference here for a 16 gallon fill-up. Which is $38.40 a month, or $499.20 a year.

Toss the extra 80 cents in for those times where you squeeze it just a hair more to get an even number and you're looking at $500 per year. Which could be ten tanks of gas.

you drive 8 tank of gas every month?

Originally Posted by jasonbimmer

you drive 8 tank of gas every month?

two fillups per week was what we were averaging in the BMW when it was being driven regularly.

My car requires premium, I use 87.
Great mileage and power.
I love gas companies and their marketing, it gets to people.
Research difference between 87-94. Lower octane is more combustible and higher octane has more retardant which means less likely to combust prematurely in the higher performance engines.

Originally Posted by ChicagoRY

This is extremely debatable. Without the ability to try to program your ignition/timing to take advantage of a higher octane fuel I don't know what good a higher octane than recommended would do.

but they were also manually setting pushing the ignition advance for each dyno run, something no "off the shelf" car can do.

Wusz [76 Chemist] said, "An engine does not know what the octane rating of the fuel is, unless it is too low"; note that we made less power by adding booster to 91-octane fuel.

Just my $0.02. . .to each his own.

Good information, the test was done on an engine without knock sensors and without an ECU that can adjust ignition timing.

Our off the shelf BMWs can and do vary the ignition timing through the use of coolant/oil Temp sensors, engine load, intake air temp, Air flow into the engine (MAF) and knock sensors

They also have an ECU data item that gives the RON octane value of the gasoline being used This is listed for technician symptom troubleshooting and can be found in the WDS BMW Wiring Diagram System - Model 3 E46
http://www.bmw-planet.com/diagrams/r.../e46/index.htm

Here is another article on increased power in a E46 M3 BMW from changing 91 pump unleaded to 93 pump unleaded :
It also uses a Siemens ECU similar to the other E46s

http://www.dinancars.com/university/
Dynamometer Testing and The Modern BMW Engine


Stock E46 M3 Ignition Timing Adaptations


The E46 M3 is an excellent example of an engine that is sensitive to octane. It has a very high volumetric efficiency as well as a very high static compression ratio of 11.5 - 1. The engine being tested was a stock M3 engine. It was first warmed up and stabilized using the method described previously for the M5, running 91-octane fuel. As you can see in Figure 22, where the engine was warmed up and the previously discussed testing procedures applied, the stock M3 produced 280 hp (Figure 22- violet line). We then replaced the 91-octane fuel with 93 (available in most parts of the country). The M3's computer was so quick to determine that the fuel had been improved that it only took four dyno runs for the timing to adapt to the increased octane and raise the power up to 291 hp (Figure 22 - light blue and yellow lines). A gain of 11 hp with just 2 points of octane.

Figures #23 and #24 below are taken directly from the BMW factory diagnostic tool, demonstrating how ignition timing adapts to different fuel octane ratings. The same car is represented here, the only difference being the octane rating of the fuel. If you were to add 1° of ignition advance, the engine management system would detect it and retard the timing 1°. You can see that adding timing in the engine management software or "power chip" is futile because the computer will negate the change, as sufficient octane does not exist. However, you can see that adding higher octane fuel is like adding a "power chip" as the system adapts to the better fuel, making more power.

Originally Posted by //TRD power

My car requires premium, I use 87.
Great mileage and power.
I love gas companies and their marketing, it gets to people.
Research difference between 87-94. Lower octane is more combustible and higher octane has more retardant which means less likely to combust prematurely in the higher performance engines.

That's seemingly logical but incorrect. Ability to combust doesn't have a linear relationship, in any direction, with propensity to knock. Chances are I'm not a chemist for a large oil & gas company and neither are you, so I don't think this is nessecarily a subject ripe for debate by the layman. But if you look at the article I linked to in my most recent post above you'll see that they did dyno pulls with 40 different tanks of gas on the same engine with various ignition timings used each time and they found:

. . .we discovered that our presumption that higher-octane fuels burn slower than lower-octane fuels (and therefore require more ignition lead) is largely incorrect. There are too many other fuel-formulation issues at work to assign a general rule about octane.

Unfortunately data that's already being collected (in house by gas/oil companies), auto manufacturers, and by 3rd parties like the EPA, and practically every single state on scientific gas analysis just isn't publicly shared, so in a "best case" scenario I'm forced to rely on 40 dyno pulls from Hot Rod Magazine. . .ha. Nevertheless, if you show me something from oil/gas company testing, SAE or SPE published journal (which charge money to read unless you're a member, which I'm not) to the contrary I'd be slack jawed.

Originally Posted by shanneba

http://www.dinancars.com/university/
Dynamometer Testing and The Modern BMW Engine


Stock E46 M3 Ignition Timing Adaptations


The E46 M3 is an excellent example of an engine that is sensitive to octane. It has a very high volumetric efficiency as well as a very high static compression ratio of 11.5 - 1. The engine being tested was a stock M3 engine. It was first warmed up and stabilized using the method described previously for the M5, running 91-octane fuel. As you can see in Figure 22, where the engine was warmed up and the previously discussed testing procedures applied, the stock M3 produced 280 hp (Figure 22- violet line). We then replaced the 91-octane fuel with 93 (available in most parts of the country). The M3's computer was so quick to determine that the fuel had been improved that it only took four dyno runs for the timing to adapt to the increased octane and raise the power up to 291 hp (Figure 22 - light blue and yellow lines). A gain of 11 hp with just 2 points of octane.

So a 3% increase in power. In a street-driven car, is it worth it?

Originally Posted by NOVAbimmer

So a 3% increase in power. In a street-driven car, is it worth it?

That is the $64000 question each of us much answer ourselves.

My question would be ..... if 91 to 93 gives 3%, would 91 to 95 give 6%.
Many here would spend mucho bucks to gain an honest 10 HP, cams, headers, software, intakes etc. ($3000 for the ZHP option)
None of that matters much for a street driven car either

I'll try to get some data in the next couple of months. I ordered some of the Torco fuel booster and will try to get to the drag strip to record times and engine data from the computer
on runs the same day with and without the additive.

Then I will have some actual data to analyze

Originally Posted by shanneba

Good information, the test was done on an engine without knock sensors and without an ECU that can adjust ignition timing.


The E46 M3 is an excellent example of an engine that is sensitive to octane. It has a very high volumetric efficiency as well as a very high static compression ratio of 11.5 - 1. The engine being tested was a stock M3 engine. It was first warmed up and stabilized using the method described previously for the M5, running 91-octane fuel. As you can see in Figure 22, where the engine was warmed up and the previously discussed testing procedures applied, the stock M3 produced 280 hp (Figure 22- violet line). We then replaced the 91-octane fuel with 93 (available in most parts of the country). The M3's computer was so quick to determine that the fuel had been improved that it only took four dyno runs for the timing to adapt to the increased octane and raise the power up to 291 hp (Figure 22 - light blue and yellow lines). A gain of 11 hp with just 2 points of octane.

Figures #23 and #24 below are taken directly from the BMW factory diagnostic tool, demonstrating how ignition timing adapts to different fuel octane ratings. The same car is represented here, the only difference being the octane rating of the fuel. If you were to add 1° of ignition advance, the engine management system would detect it and retard the timing 1°. You can see that adding timing in the engine management software or "power chip" is futile because the computer will negate the change, as sufficient octane does not exist. However, you can see that adding higher octane fuel is like adding a "power chip" as the system adapts to the better fuel, making more power.

Thank you for the input, I love good first hand data, or closer to first hand! However, most of what you said is totally spurious to any point I intended to make.

1. I say in the beginning of my post "87 vs 91/93," because most places, like where 50% or so of US pop lives is in a EPA reformulated zone, for me 91 is the highest octane available within like 8 surrounding counties. "Most of the US" does NOT have access to 93 at their local gas station (I dispute that claim in your quote), most of the US by landmass size, sure. Most of the US by population? I have no idea. But 80% of the US pop lives in an urban area, reformulated gas will be law in more places than not as time marches on. I lumped them together because I figure an M3 owner looking for most performance will use the highest octane gas available. For purposes of answering the OP question there is no need to differentiate between 91 and 93 octane pump gas, just assume he's starting off with the highest octane available. (PS - when 93 is your premium, what's your mid grade? For us it's 89).



1b. An aside, not really relavent to the OP question, but more towards that data you are citing. . .I've already read where BMW states their vehicles to the US are "tuned to use, and tested with premium." If I was a betting man I'd bet that they are tuned to use 93. Like I mentioned elsewhere (this thread way back? I forget) I run 91 and can and do get occasional knocks (that I never hear) but are stored, and visible when I pull all the codes out. Not visible in a "CEL is triggered, connect the Peake scanner" way.

2. What you said about the BMW ECU and it compensating timing for advance may be totally true, but I gave an example from my own personal vehicle (a 1994 Chevy Impala SS that I used to own) that dropped about .3 of a sec and gained 1mph in the 1/4 mile by nothing other than a PCM re-flash that also required high octane fuel. That's a loose average over 10ish before runs, and 10ish after runs. Here's a picture of it at the track. Somewhere I have the time slips scanned. I know this is an e46 forum, I'm just trying to make the point that after market modifications to OEM software are possible and will continue to be. Most Honda guys that want to tune their cars rip out it's OE PCM and put in a different one altogether. . .aftermarket will always find ways to continue this.

3. I was looking for your charts, but your link only brought up Dinan, and I didn't see the charts you mention on the page you mention. I'm just curious to see them, thus far we're really not in disagreement here. Let's call Dinan and ask them what changes their chips make to the car with and without the addition of cams, intake, etc., and how they are getting all those gains by software alone if the ECU "compensates" right back to such changes. Don't ask me, I will not claim to be an expert in this!

4. I have an ersatz GT1, tell me what data you want to see and we can run it. I'm just trying to address OP's question about supplemental octane boosters.

5. The reason I cited those dyno pulls was because they use regular, premium, and each of those with supplemental octane booster. They both state and I think it's widely accepted, that higher octane gas out of a pump (be it 93 octane, 104 race gas, 110 aviation fuel etc.) is fundamentally different than pump gas with an OTC octane booster poured in the gas tank.

Are you disagreeing with anything I'm saying here?

Like I said. . ."octane boosters. . .hotly contested. . ."

Originally Posted by shanneba

That is the $64000 question each of us much answer ourselves.

My question would be ..... if 91 to 93 gives 3%, would 91 to 95 give 6%.
Many here would spend mucho bucks to gain an honest 10 HP, cams, headers, software, intakes etc. ($3000 for the ZHP option)
None of that matters much for a street driven car either

I'll try to get some data in the next couple of months. I ordered some of the Torco fuel booster and will try to get to the drag strip to record times and engine data from the computer
on runs the same day with and without the additive.

Then I will have some actual data to analyze

It's not a $64k question, it's it's 2 x $200 questions if you want to be super accurate. That's how much an hour of dyno time costs around me anyway x 2 hour long sessions. But like I mention above, huge difference if you're testing 93 pump gas vs. 93 pump gas + octane booster, or testing it vs. a higher octane racing gas. If you want to run 110 octane stop at an airport, a municipal one if you're near one, and grab a 2 gallon fill of 110 octane avgas.

Or probably, a 10 min call to Dinan, they've been messing with BMW reprogramming for longer than I've had my BMW (11 years).

And I totally agree with your last sentence "some actual data," on any car I've had where I do a mod that should impact (hopefully) my acceleration (peak torque/peak hp) I have tested that car before and after at the closest drag strip. The closest drag strip to me is about an hour, costs $25, and is considerably more fun than a dyno. But your point about "people will drop money [paraphrased]. . . ." couldn't be more true, car guys anywhere throw money into fun mods, but it's totally impossible IMHO to "feel" a change and the direction of that change one small mod at a time. Put in a blower, ya it will be noticeable by seat of the pants. Still, I'd like to know the hard #s on it. . .and roundabout HP calculations are backwards calculable from dragstrip ETs, unfortunately we can't make dyno plots from ETs though. A lot of people gain peak hp but trade off hp that's way more in the section of "commonly usable power 1k rpm-3k rpm," and they don't really even realize it. Oh cars. . .sigh.

Originally Posted by ChicagoRY

Thank you for the input, I love good first hand data, or closer to first hand! However, most of what you said is totally spurious to any point I intended to make.

1. I say in the beginning of my post "87 vs 91/93," because most places, like where 50% or so of US pop lives is in a EPA reformulated zone, for me 91 is the highest octane available within like 8 surrounding counties. I lumped them together because I figure an M3 owner looking for most performance will use the highest octane gas available. For purposes of answering the OP question there is no need to differentiate between 91 and 93 octane pump gas. (PS - when 93 is your premium, what's your mid grade? For us it's 89)





2. What you said about the BMW ECU and it compensating timing for advance may be totally true, but I gave an example from my own personal vehicle (a 1994 Chevy Impala SS that I used to own) that dropped about .3 of a sec and gained 1mph in the 1/4 mile by nothing other than a PCM re-flash that also required high octane fuel. That's a loose average over 10ish before runs, and 10ish after runs. Here's a picture of it at the track. Somewhere I have the time slips scanned.

3. I was looking for your charts, but your link only brought up Dinan, and I didn't see the charts you mention on the page you mention. I'm just curious to see them, thus far we're really not in disagreement here. Also instead of quoting large chunks of Dinan's webpage (ps - if you're going to quote something from a website, put it in quotes or italics, you're using 'we' in those paragraphs like they are stuff you authored), let's call Dinan and ask them what changes their chips make to the car with and without the addition of cams, intake, etc., and how they are getting all those gains by software alone if the ECU "compensates" right back to such changes. Don't ask me, I will not claim to be an expert in this!

4. I have an ersatz GT1, tell me what data you want to see and we can run it. I'm just trying to address OP's question about supplemental octane boosters.

5. The reason I cited those dyno pulls was because they use regular, premium, and each of those with supplemental octane booster. They both state and I think it's widely accepted, that higher octane gas out of a pump (be it 93 octane, 104 race gas, 110 aviation fuel etc.) is fundamentally different than pump gas with an OTC octane booster poured in the gas tank.

Are you disagreeing with anything I'm saying here?

Like I said. . ."octane boosters. . .hotly contested. . ."

1. Not all areas that have EPA mandated reformulated gas have 91 premium.
Houston has reformulated gas but most stations have 93 premium and mid grade is still 89, they just mix less premium with the regular 87.

2. I can see changes in ignition timing when I hit an interstate overpass with cruise set , the load signal goes up, the throttle opens slightly, the intake air temp sometimes drops, the ignition timing changes, the injection duration may also increase slightly.

3. Dinan seems to have lost the charts when they updated their web site.
The text from the Dinan site IS in italics in my post

I can say that Dinan most likely isn't adding ignition timing to increase power.
I did see a change in my Long term fuel trims when I had the Stage two software installed, it indicated it was running richer on the same tank of gas on the same day. 14.7:1 doesn't produce the most power OR the most gas mileage, just the lowest overall emissions. I suspect Dinan does most of the changes with fuel trims when the O2 sensors go to open loop under full throttle but I do not have access to the code to confirm

4. I monitor the engine rpm, vehicle speed, coolant temp, coolant temp at the radiator outlet, oil temp, intake air temp, ignition timing, injection duration, and sometimes load signal, MAF output, VANOS actual intake and exhaust position, and RON factor. I usually record the data using AutoEnginuity Software. There aren't that many data points in a 15 second 1/4 mile run if I attempt to collect too many data items.

5. there are many ways to create with high octane unleaded. Even the pump gas from the same refinery varies from day to day.

I am not disagreeing with most of what you said, mostly just trying to say that our cars do vary the ignition timing constantly and can detect the RON value of the gasoline being used by measuring the various data inputs.


I can run down the street and purchase Sunoco GT260 100 octane unleaded at a speedway station.
You can probably find it in Chicago too - http://www.racegas.com/fuelfinder

8424 Willow Springs Road, Willow Springs, IL 60480
18460 80th Ave., Tinley Park, IL 60487
7405 Calumet Ave., Hammond, IN 46324

Originally Posted by JohnIBarr01

+1, how did I get tricked into coming back to this thread?!

How come all the threads I post to turn out to be like dirty prison rapes? I must be a dirty prison rape instigator. . .however in these kinds of dirty prison rapes, unlike the real ones - nobody leaves with a smile on their face.

I was totally suckered into this time, I have no one to blame but me! Someone mentions "octane boosters" and I'm dumb enough to chime in and contribute to a giant flow chart of time wasting spread across the globe.

Even if this tread dies......... someone will ask the same question in the next two weeks........

Originally Posted by ChicagoRY

+1, how did I get tricked into coming back to this thread?!

How come all the threads I post to turn out to be like dirty prison rapes? I must be a dirty prison rape instigator. . .however in these kinds of dirty prison rapes, unlike the real ones - nobody leaves with a smile on their face.

I was totally suckered into this time, I have no one to blame but me! Someone mentions "octane boosters" and I'm dumb enough to chime in and contribute to a giant flow chart of time wasting spread across the globe.

^^^ silly

I said prison, not a spaceship!

Originally Posted by shanneba

Even if this tread dies......... someone will ask the same question in the next two weeks........

Someone ought to make a plugin for V bulletin where if I start a new thread, as I type in for subject "O C T A "

then boom, it suggests the 15 threads from the past that have the word "octane" in the thread subject

Originally Posted by NOVAbimmer

two fillups per week was what we were averaging in the BMW when it was being driven regularly.

if you drive that often, you might consider something more economical.