E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > E46 BMW > General E46 Forum

General E46 Forum
This is the place to get answers, opinions and everything you need related to your E46 (sedan, coupe, convertible and wagon) BMW!

Reply
 
Thread Tools Search this Thread Rating: Thread Rating: 3 votes, 5.00 average. Display Modes
Old 04-09-2012, 08:44 PM   #81
tedelex06
Registered User
 
Join Date: Oct 2011
Location: Brisbane
Posts: 165
My Ride: E46 323i S/C
89? lolwut.

In Australia the lowest octane available is 91, which is the 'economy fuel' (cheaper)

Then there is regular unleaded, about 93 (i think?), premium 95, premium 98 and premium 100 octane fuels.
tedelex06 is offline   Reply With Quote
Old 04-09-2012, 08:54 PM   #82
JohnIBarr01
Registered User
 
Join Date: Mar 2012
Location: Knoxville, TN; Apex, NC
Posts: 582
My Ride: ZHP 6MT, Mk.6, Jeep
Quote:
Originally Posted by tedelex06 View Post
89? lolwut.

In Australia the lowest octane available is 91, which is the 'economy fuel' (cheaper)

Then there is regular unleaded, about 93 (i think?), premium 95, premium 98 and premium 100 octane fuels.
You're on the RON scale, not the North American AKI scale
__________________
Pat Summitt Foundation | VWvortex | V2Lab | Twitter | Facebook
Quote:
Originally Posted by TheGreenspanator
Let me guess: This doesn't happen in Germany
JohnIBarr01 is offline   Reply With Quote
Old 04-09-2012, 09:02 PM   #83
jdstrickland
Registered User
 
Join Date: Apr 2010
Location: Murrieta, CA
Posts: 6,949
My Ride: '94 325iC & '00 323i
Quote:
Originally Posted by NOVAbimmer View Post
Claiming "my mpg is better now than then" is nearly impossible to nail down to a single factor such as fuel selection. Even getting your gas at a different station, or from a different pump at the same station can introduce variables.

Just because you set your cruise at "x" speed doesn't mean the drive was exactly the same. What's the elevation change between point a and b? Which was was the wind blowing? How much other traffic was on the road? What was the barometric pressure?

Given the right conditions, we could probably set up an experiment to show our cars getting better mileage than a hybrid.
Which is why you average at least 5 tanks of gas. You could average 3 tanks, but the variations would be more pronounced. If you aveage 10 tanks, it could take a while, but at the end of the test, you would have good numbers but it would take a year for most of us to pump 20 tanks of fuel -- 10 at one grade and 1q0 more at the other.

Most of us schlep along in our daily drive doing the same trip over and over again, and there really are not many variants that can enter into the formula. But if one averages the fuel economy over time and distance, then the number for the consumption rate flattens out. If you got 22.3, 24.5 23.8, 24.2, and 22.7, then the average is 23.5. You can calculate the average cost of a gallon, and then calculate the mpg that would be needed to support the next higer grade. Then run 5 tanks of that to see if you beat that number, if yes, then the higher grade costs less, if no, the you spent less than 10 bucks finding this out.

My experience is that the higher grade -- mid-grade over regular -- is cheaper. Premium is a bust, the numbers don't pan out. Don't get me wrong, I use Premium when I fill at Costco because it is the same price as the mid-grade where I usually fill up. I never buy regular because when I tested it, it actually cost more per mile, which is what you really want to figure out.
jdstrickland is offline   Reply With Quote
Old 04-09-2012, 09:03 PM   #84
jdstrickland
Registered User
 
Join Date: Apr 2010
Location: Murrieta, CA
Posts: 6,949
My Ride: '94 325iC & '00 323i
Quote:
Originally Posted by tedelex06 View Post
89? lolwut.

In Australia the lowest octane available is 91, which is the 'economy fuel' (cheaper)

Then there is regular unleaded, about 93 (i think?), premium 95, premium 98 and premium 100 octane fuels.
You have RON, not AKI.
jdstrickland is offline   Reply With Quote
Old 04-09-2012, 09:11 PM   #85
jdstrickland
Registered User
 
Join Date: Apr 2010
Location: Murrieta, CA
Posts: 6,949
My Ride: '94 325iC & '00 323i
Quote:
Originally Posted by BuddyBuddy View Post
Although my "testing" over the weekend showed less than 1% difference between "regular" and "premium" gas, others have pointed out that there are other differences and they are basically correct.
Speaking only for the US, different parts of the country get different blends of fuel at different parts of the year.
In Chicago, we get a "winter blend" that always gets blamed for an increase in fuel prices.
When the winter blend is gone, it also gets blamed for an increase in fuel prices in the Spring.

Also- you know those signs at the pump that say "may contain UP TO 10% Ethanol"? Ethanol is used as an octane booster, so guess which fuel has the most ethanol?
Premium. At least in my area. And ethanol has about 30% less energy released when burned than gasoline.
After 10 years of driving back and forth between Chicago and Atlanta, I've noticed a marked difference (10% increase) in milage once I start filling up in Southern Indiana and parts south. I do not know what is different about the fuel, but I get better milage and it is cheaper.

Comparing milage and fuels around the country(s) becomes rather difficult because of variables like this as well as your tires, the road surface, your speed, head winds....
Your testing over a weekend is far too short to draw any viable conclusion, other than the test is too short. Ethanol is not an ocatane booster. Well, it coulld be, but that's not why they use it. Ethanol is used to displace petroleum. Period. We can suck all of the corn from the food chain and increase the price of all foods, but we can make more ethanol forever as long as we we have 25 gallons of water for every gallon of ethanol produced. Ethanol is a false economy, we can make more which means it is a renewable resource, but the cost to the food chain and the demand for water may well be more than the benefit of making more ethanol.

My nose is bleeding, I have to climb down from my soap box...
jdstrickland is offline   Reply With Quote
Old 04-09-2012, 10:08 PM   #86
ChicagoRY
Registered User
 
Join Date: Sep 2011
Location: Portland, OR
Posts: 597
My Ride: 2002 E46
Quote:
Originally Posted by NOVAbimmer View Post
No, I'm just using anecdotal evidence to support my hypothesis that premium fuel offers zero advantage to my naturally aspirated, mass-produced cars.

Anyone have an idea of how much better mileage premium could potentially get you?
It's not about mileage, on a vehicle that requires/is tuned for 87 octane it will not get better mileage when filled with 91 octane. A vehicle tuned/calling for 91 octane will not get insanely worse mileage on 87 octane.

Here, from the horses mouth, no seats of the pants anecdotes. . .especially when a lot of what we're talking about here is longer term effects (hence my head inspection challenge earlier in the thread).

BMW Product Communications
Thomas Plucinsky, Product Communications Manager
Tel: 201-307-3783
Email: Thomas.Plucinsky@bmwna.com


LA Times, March 29 2012
"If you use fuel with the lower octane rating, our engines will deal with it," said Thomas Plucinsky, a spokesman for BMW. "But why would you do it in a car like our 335i? You are not getting the power and performance you are expecting and paid for."

Running On Regular: Do Premium Vehicles Really Need Premium Gasoline?
Thomas Plucinsky, BMW Product and Technology Communications Manager told us all BMW engines are designed to run on 91 octane. All performance testing, including EPA emissions and fuel mileage, is done with 91 octane. However, though BMW is all about performance, their motors will run on 89 or 87 octane without damage. The knock sensors pull the ignition timing back and eliminate detonation. There will be a loss of power and a decrease in fuel mileage, but the size of the horsepower loss and the increase in fuel consumption depends upon many factors, such as ambient temperature, exact formulation of the fuel and driving technique, so BMW does not offer any estimates for operation on lower grade fuels. One not so obvious concern, Mr. Plucinsky noted, is the type and quality of additives the gasoline companies include in the fuel. Premium gasolines may have better additive packages which are more effective keeping fuel systems (particularly injectors) clean and working efficiently, than those in regular grade fuels or off-brand products. Using lower octane or off-brand fuel could be degrading the fuel system over time, setting you up for a repair bill down the line.

And I recommended earlier reading about BMW's recommendation of "Top Tier" approved gasolines, and found the testing criteria here. I don't understand it all, but it's pretty interesting nonetheless. A gas manufacturer has to pay $30k to submit samples to be tested for Top Tier approval.

Last edited by ChicagoRY; 04-09-2012 at 10:11 PM.
ChicagoRY is offline   Reply With Quote
Old 04-09-2012, 11:40 PM   #87
ac_2007
Registered User
 
ac_2007's Avatar
 
Join Date: Apr 2010
Location: Toronto
Posts: 6,992
My Ride: F32 M4, E46 M3/325i
Quote:
Originally Posted by NOVAbimmer View Post
No, I'm just using anecdotal evidence to support my hypothesis that premium fuel offers zero advantage to my naturally aspirated, mass-produced cars.

And it's not a theory I have any interest in disproving, so I'm admittedly biased.

I'm not going to any lengths to participate in a scientific experiment, either.

Anyone here can disprove it with a claim that 93 gets them 3.75648% better gas mileage, thereby throwing off my calculation.

But looking at a national average of about $4 per gallon regular, and a national average of $4.20 premium, you need to get 5% better fuel mileage from premium to offset the price difference.

Anyone have an idea of how much better mileage premium could potentially get you?
You'll not only get better mileage per tank, but more horsepower if the engine is tuned for higher octane. The 6-cyl E46's are.
In the end with the extra mileage from premium, I still won't ever break even given the prices here. In the states you will.

Doesn't matter, I like to get all my measly 192hp. Did I mention my mom makes me lunch?





Everyone watch this video, now. Do it!

__________________
ac_2007 is offline   Reply With Quote
Old 04-10-2012, 01:18 AM   #88
Mango
A full five stars, son
 
Mango's Avatar
 
Join Date: Mar 2006
Location: Southern California
Posts: 22,807
My Ride: M54B30
cool video!
__________________
A lifetime free of problems if you follow my guides
Cooling | Maintenance | Suspension | Vacuum | Supreme Reliability | Details

OVER A MILLION VIEWS
Mango is offline   Reply With Quote
Old 04-10-2012, 01:27 AM   #89
Vigilante
Registered User
 
Join Date: Feb 2011
Location: Amsterdamned, Dutchland ;)
Posts: 260
My Ride: 320i - 2.2 L - 170hp
Send a message via MSN to Vigilante
interesting vid, scary man I always go to BP but now there is a new Shell at the opposite side off the road. I don't need the extra power, I have a lazy foot, but it's cheaper
__________________
320i Executive Sedan | E46_AV11 | ZF5HP19 S-t | M54B22 | 170hp 210Nm | 09/2000 | 143k | 30.6 MPG
Maintenance
Re-surfaced CH | VC+VCG | CAM/VANOS timing | IMG | NGK-i | BAT+ALT | O2's | GM5 | WP WPP | PSP | DISA | TB ICV MAF | CCV | CAI | OFHG | FP | FF | A/C | FSU | AUC | WSS | BL BD BP | E46Mango! | JFOJ | SB TP IP | springs | Shocks |tires | ASC+ | alignment | E.Flush | Castrol SAF-XJ 75W140 | ZF LGF5 ATF Flush
Planned
FCA+FCAB | Struts

Last edited by Vigilante; 04-10-2012 at 01:37 AM.
Vigilante is offline   Reply With Quote
Old 04-10-2012, 07:36 AM   #90
ChicagoRY
Registered User
 
Join Date: Sep 2011
Location: Portland, OR
Posts: 597
My Ride: 2002 E46
Quote:
Originally Posted by Vigilante View Post
interesting vid, scary man I always go to BP but now there is a new Shell at the opposite side off the road. I don't need the extra power, I have a lazy foot, but it's cheaper
I don't know about their non-US formulations, but FWIW BP isn't on the "top tier" list (confusingly I want to say "top gear" every time) but Shell is.

However I hear in Amsterdam you have more serious things to deal with when driving, like canals.
ChicagoRY is offline   Reply With Quote
Old 04-10-2012, 07:45 AM   #91
NOVAbimmer
Registered User
 
Join Date: Aug 2006
Location: VA
Posts: 12,465
My Ride: 14 Impala FXST M796
Quote:
Originally Posted by ChicagoRY View Post
It's not about mileage, on a vehicle that requires/is tuned for 87 octane it will not get better mileage when filled with 91 octane. A vehicle tuned/calling for 91 octane will not get insanely worse mileage on 87 octane.

Here, from the horses mouth, no seats of the pants anecdotes. . .especially when a lot of what we're talking about here is longer term effects (hence my head inspection challenge earlier in the thread).

BMW Product Communications
Thomas Plucinsky, Product Communications Manager
Tel: 201-307-3783
Email: Thomas.Plucinsky@bmwna.com


LA Times, March 29 2012
"If you use fuel with the lower octane rating, our engines will deal with it," said Thomas Plucinsky, a spokesman for BMW. "But why would you do it in a car like our 335i? You are not getting the power and performance you are expecting and paid for."

Running On Regular: Do Premium Vehicles Really Need Premium Gasoline?
Thomas Plucinsky, BMW Product and Technology Communications Manager told us all BMW engines are designed to run on 91 octane. All performance testing, including EPA emissions and fuel mileage, is done with 91 octane. However, though BMW is all about performance, their motors will run on 89 or 87 octane without damage. The knock sensors pull the ignition timing back and eliminate detonation. There will be a loss of power and a decrease in fuel mileage, but the size of the horsepower loss and the increase in fuel consumption depends upon many factors, such as ambient temperature, exact formulation of the fuel and driving technique, so BMW does not offer any estimates for operation on lower grade fuels. One not so obvious concern, Mr. Plucinsky noted, is the type and quality of additives the gasoline companies include in the fuel. Premium gasolines may have better additive packages which are more effective keeping fuel systems (particularly injectors) clean and working efficiently, than those in regular grade fuels or off-brand products. Using lower octane or off-brand fuel could be degrading the fuel system over time, setting you up for a repair bill down the line.

And I recommended earlier reading about BMW's recommendation of "Top Tier" approved gasolines, and found the testing criteria here. I don't understand it all, but it's pretty interesting nonetheless. A gas manufacturer has to pay $30k to submit samples to be tested for Top Tier approval.
Speculation from someone working for BMW sticking with the company line? Then he appeals to a BMW owners ego? This guy is ready for the high school debate team.

You can walk into any dealership and get the exact same spiel from a salesman.

If a BMWNA rep suddenly said "yeah, use whatever gas you want", suddenly all BMWs literature to date is wrong.

As far as power goes, yes you will most likely lose some. For instance, the Mustang GT is tuned for 91 octane. They tell you there is no problem running the car on 87 octane, but the car adjusts timing and the power cuts by 3%. Again, your butt dyno isn't that sensitive.

Maybe it is, though, in which case, modding must be a blast, as everything creates a noticeable difference.
__________________
NOVAbimmer is online now   Reply With Quote
Old 04-10-2012, 08:47 AM   #92
ChicagoRY
Registered User
 
Join Date: Sep 2011
Location: Portland, OR
Posts: 597
My Ride: 2002 E46
Quote:
Originally Posted by NOVAbimmer View Post
Speculation from someone working for BMW sticking with the company line? Then he appeals to a BMW owners ego? This guy is ready for the high school debate team.

You can walk into any dealership and get the exact same spiel from a salesman.

If a BMWNA rep suddenly said "yeah, use whatever gas you want", suddenly all BMWs literature to date is wrong.

As far as power goes, yes you will most likely lose some. For instance, the Mustang GT is tuned for 91 octane. They tell you there is no problem running the car on 87 octane, but the car adjusts timing and the power cuts by 3%. Again, your butt dyno isn't that sensitive.

Maybe it is, though, in which case, modding must be a blast, as everything creates a noticeable difference.

Hey - I posted the quotes because a lot of jackasses here like to cite anecdotal examples and butt dynos. I figured something from a BMW spokesperson, the people who make the car and pay for warranty claims, might be better accepted than most other random comments here. I also included his email address for the specific purpose that anyone who wants more information can email him and ask for it.

For agreeing with my point (that I've tried to nicely state a handful of times in this thread), why are you simultaneously being a bit hostile?

Leave out the "high school debate team" and "appealing to ego" crap and just state some facts. You're ridiculing people for debating emotionally with their butt dynos while instigating an emotive reaction with comments pretty much unrelated to the topic at hand. (side note, my high school taught far better debate than that technique)

I try to provide quotes and links to first hand sources with some legitimacy because I think it's generally more helpful than most ideas that would be purely attributable to me. In fact I'm pretty sure that's the commonly accepted procedure for scientific and technical writing.

Maybe I'm reading too much into your post, or one or the both of us got up on the wrong side of bed (my bed slants to the wrong side). . .I just thought it was very bizarre that the majority of it was dissing my source, then it came around and at the end it concurred with the same statement I've made 5 different ways. Is he the world's best source? No. . .however, the public doesn't have good access to the internal testing of EPA, car manufacturers, or gasoline refineries - swear to god, I've checked, intensively. But like I said, that's why I posted his email address, maybe if you paypal him a $20 spot he can cough up some German MS Excel spreadsheets.

PS - I would bet heavily on the BWM people out of New Jersey vs. my local dealership if there was a fact test of some kind going on. . .no disrespect to those who sell cars but they tend to be more sales oriented and less facts and figures and TSBs and ETKA knowledgeable.

PPS - No modern engine will make a hard and fast % cut of "power output." The IAT on a 90deg F day vs a 40deg F day could potentially have a similar effect on the intake charge as a reduction in octane might exhibit. An ECU might determine not to reduce an engine's power at all in that case, all other things being equal. Will your 1/4 mile time be different, ya probably because that's a WOT sustained blast. Anyone that pays attention and has had a car with forced induction tends to be acutely aware of temperature and altitude difference. Chicago and turbo Audis have been fun to be over the years since it's sorta chilly here like 8 months out of the year.

Last edited by ChicagoRY; 04-10-2012 at 08:53 AM.
ChicagoRY is offline   Reply With Quote
Old 04-10-2012, 08:57 AM   #93
NOVAbimmer
Registered User
 
Join Date: Aug 2006
Location: VA
Posts: 12,465
My Ride: 14 Impala FXST M796
The only part of my post that was directed at you was the point about the BMWNA rep sticking to the company line. No matter how many times we ask him, he will always remind us that BMW recommends 91 octane in all vehicles.

His statement of "why would you want to put anything less into your brand new 335" is an emotional appeal to the egos of BMW drivers.

And yes, we do agree that running lower octane results in less power from retarded timing. I'm arguing, though, that you will never notice the difference, and that you will suffer no negative consequences, long- or short-term, from running 87 octane. As long as you're buying from a respectable station (top tier gas), my argument is that you'll have no issues running 87, regardless of what BMW may tell us.

Just like BMW recommends only BMW oil, we still use Mobil, Castrol, Penzoil, heck, some of us even use non-LL01 spec oils.

(For everyone)
Choice of fuel grade is a personal one, motivated by your own ego and wallet. Choose what you want, but don't believe you're superior based on your fuel choice.
__________________
NOVAbimmer is online now   Reply With Quote
Old 04-10-2012, 09:40 AM   #94
Vigilante
Registered User
 
Join Date: Feb 2011
Location: Amsterdamned, Dutchland ;)
Posts: 260
My Ride: 320i - 2.2 L - 170hp
Send a message via MSN to Vigilante
Quote:
Originally Posted by ChicagoRY View Post
However I hear in Amsterdam you have more serious things to deal with when driving, like canals.
Nope, we solved that problem as well

Van Drop Box
Attached Thumbnails
Click image for larger version

Name:	Canal bus.jpg
Views:	24
Size:	221.0 KB
ID:	445896  
__________________
320i Executive Sedan | E46_AV11 | ZF5HP19 S-t | M54B22 | 170hp 210Nm | 09/2000 | 143k | 30.6 MPG
Maintenance
Re-surfaced CH | VC+VCG | CAM/VANOS timing | IMG | NGK-i | BAT+ALT | O2's | GM5 | WP WPP | PSP | DISA | TB ICV MAF | CCV | CAI | OFHG | FP | FF | A/C | FSU | AUC | WSS | BL BD BP | E46Mango! | JFOJ | SB TP IP | springs | Shocks |tires | ASC+ | alignment | E.Flush | Castrol SAF-XJ 75W140 | ZF LGF5 ATF Flush
Planned
FCA+FCAB | Struts
Vigilante is offline   Reply With Quote
Old 04-10-2012, 09:55 AM   #95
Mango
A full five stars, son
 
Mango's Avatar
 
Join Date: Mar 2006
Location: Southern California
Posts: 22,807
My Ride: M54B30
Quote:
Originally Posted by NOVAbimmer View Post
The only part of my post that was directed at you was the point about the BMWNA rep sticking to the company line. No matter how many times we ask him, he will always remind us that BMW recommends 91 octane in all vehicles.

His statement of "why would you want to put anything less into your brand new 335" is an emotional appeal to the egos of BMW drivers.

And yes, we do agree that running lower octane results in less power from retarded timing. I'm arguing, though, that you will never notice the difference, and that you will suffer no negative consequences, long- or short-term, from running 87 octane. As long as you're buying from a respectable station (top tier gas), my argument is that you'll have no issues running 87, regardless of what BMW may tell us.

Just like BMW recommends only BMW oil, we still use Mobil, Castrol, Penzoil, heck, some of us even use non-LL01 spec oils.

(For everyone)
Choice of fuel grade is a personal one, motivated by your own ego and wallet. Choose what you want, but don't believe you're superior based on your fuel choice.

For an extra $3 short term per tank and better fuel economy long-term, no reason NOT to use premium. With 87, you're actually PAYING to screw yourself.

It has nothing to do with ego but doing what's best for your car. We bought BMWs to begin with because we like performance. (Could've settled on an Accord or Camry??) Why one would do anything to reverse that performance is beyond me.
__________________
A lifetime free of problems if you follow my guides
Cooling | Maintenance | Suspension | Vacuum | Supreme Reliability | Details

OVER A MILLION VIEWS
Mango is offline   Reply With Quote
Old 04-10-2012, 11:19 AM   #96
BuddyBuddy
Registered User
 
Join Date: Feb 2012
Location: chicago
Posts: 35
My Ride: 2002 330cic
ethanol not an octane booster? since when?

Quote:
Originally Posted by jdstrickland View Post
Ethanol is not an ocatane booster. Well, it coulld be, but that's not why they use it. Ethanol is used to displace petroleum. Period.

ooo... "period." end of story!

really? citation please. Love to hear from an authoritative source than Ethanol is not used as an octane booster in gasoline and that it is used as a filler, or something else instead.

here are couple of citations regarding ethanol and its current use as an octane booster:

this one describes how it was used to replace MTBE:
http://www.eia.gov/forecasts/steo/sp...df/mtbeban.pdf

http://web.extension.illinois.edu/ethanol/vehicles.cfm

there are more.
__________________
BuddyBuddy is offline   Reply With Quote
Old 04-10-2012, 01:16 PM   #97
Geo31
Ironman
 
Join Date: Mar 2003
Location: Houston, TX, USA
Posts: 1,175
My Ride: 00 328i, 98 M Roadie
Quote:
Originally Posted by NOVAbimmer View Post
His statement of "why would you want to put anything less into your brand new 335" is an emotional appeal to the egos of BMW drivers.

And yes, we do agree that running lower octane results in less power from retarded timing. I'm arguing, though, that you will never notice the difference, and that you will suffer no negative consequences, long- or short-term, from running 87 octane. As long as you're buying from a respectable station (top tier gas), my argument is that you'll have no issues running 87, regardless of what BMW may tell us.
Maybe, maybe not. I do find it funny when people buy a premium product and then get less than the best out of it for trying to pinch a few pennies. Some people will spend hours arguing about their car's hp from the factory vs another, or spend $$$$$$$$ on mods to supposedly make the car faster, yet again, will pinch pennies and undercut the whole gain.

People seem to have a lot of passionate (and often poorly informed) arguments on this matter (NOT saying you are poorly informed NOVAbimmer - just saying in general).

For an interesting technical read on the matter or octane and AKI, read the Gasoline FAQ:

http://www.faqs.org/faqs/autos/gasoline-faq/

It's a long and technical read and there are no pictures (which will eliminate a third of those arguing ) but worth the effort if you value facts over feelings. Interesting bit about how and why the MON was developed.
__________________
George Roffe

Swim: 2.4 Miles
Bike: 112 Miles
Run: 26.2 Miles
Brag: For the rest of your life


Geo31 is offline   Reply With Quote
Old 04-10-2012, 01:43 PM   #98
DHK
Registered User
 
Join Date: Mar 2012
Location: Estonia
Posts: 681
My Ride: 2002 BMW 325Ci
The only car from the video comparable to an e46 is the Golf GTI.

The Impreza has a turbocharger which makes high octane fuel an absolute must.
The gains on the GTI were modest at best. Which points to the overall theme of this thread... Yes premium is better, but not by that much.
DHK is offline   Reply With Quote
Old 04-10-2012, 02:00 PM   #99
NOVAbimmer
Registered User
 
Join Date: Aug 2006
Location: VA
Posts: 12,465
My Ride: 14 Impala FXST M796
Quote:
Originally Posted by E46Mango View Post
For an extra $3 short term per tank and better fuel economy long-term, no reason NOT to use premium. With 87, you're actually PAYING to screw yourself.

It has nothing to do with ego but doing what's best for your car. We bought BMWs to begin with because we like performance. (Could've settled on an Accord or Camry??) Why one would do anything to reverse that performance is beyond me.
Again, what's the HP difference between 87 and 91 octane gas? Is my "performance" car going to have a noticeable difference while going up and down the road every day commuting to work?

Is this difference going to be noticeable enough to make the difference worth it over the life of the car?

And again, my Mustang gets less than 3% worse HP numbers claimed by the factory on 87 vs 91. 412 chp down to 400 chp. Even there, the money difference isn't worth it for every day driving on the street.

20, 30 years ago, I would have completely agreed with you. Any car running a decently high amount of compression required higher octane fuel in order to prevent detonation leading to severe engine damage. But not with a naturally aspirated car today.
__________________
NOVAbimmer is online now   Reply With Quote
Old 04-10-2012, 02:50 PM   #100
Mango
A full five stars, son
 
Mango's Avatar
 
Join Date: Mar 2006
Location: Southern California
Posts: 22,807
My Ride: M54B30
Quote:
Originally Posted by NOVAbimmer View Post
Again, what's the HP difference between 87 and 91 octane gas? Is my "performance" car going to have a noticeable difference while going up and down the road every day commuting to work?

Is this difference going to be noticeable enough to make the difference worth it over the life of the car?

And again, my Mustang gets less than 3% worse HP numbers claimed by the factory on 87 vs 91. 412 chp down to 400 chp. Even there, the money difference isn't worth it for every day driving on the street.

20, 30 years ago, I would have completely agreed with you. Any car running a decently high amount of compression required higher octane fuel in order to prevent detonation leading to severe engine damage. But not with a naturally aspirated car today.
Well my car has a specific tune for 91, personally.

But generally speaking, lets say you don't feel the difference. Whats to stop you from using 85 octane (if it existed) or 83? (assuming knock sensors could compensate) how far will you go? Where do you draw the line?

Being passionate about cars, and one's own car specifically, one would put the fuel in their car that delivers the best results. Nobody will argue that higher octane provides more performance and better economy.

In the end it doesn't really cost you more. In fact, it costs you less. So why not? win/win vs. lose/lose

Why replace your air filter at 15k miles? Wait until 40k. I'm sure you won't notice the extra power your car could potentially make with a clean filter.

Next up: a thread on cleaning your windows. Why clean your windows? Sure you can see better, but is it worth the effort of moving your arms back and forth?

I love you, Nova. but not today.
__________________
A lifetime free of problems if you follow my guides
Cooling | Maintenance | Suspension | Vacuum | Supreme Reliability | Details

OVER A MILLION VIEWS
Mango is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON





All times are GMT -5. The time now is 06:23 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use