[vbb]

And no, I'm not talking about what happens when you eat a lot of beans.

A lot of people on here attribute many of their car's problems to getting a bad tank of gas. What exactly does this mean? I know each gas company uses slightly different cleansers in their blends, but there are EPA standards that each company needs to follow. What is it that makes a particular company or particular tank of gas bad? What are the accepted good companys, and what are the recognized bad ones?

In my area, premium is 93oct. I don't get gas from WaWa, because they use a max of 92oct for some reason. Exxon, Citgo, and BP are pretty much everywhere though, and I've used all of them before. There are a bunch of Shell stations as well, and I fill up there most of the time. There's only a handful of Sunoco's in the area, and none are closer than 10 miles to my house.

Should I only use Shell and skip the others? Should I drive out of my way to get Sunoco?

[cn555ic]

try to fill up from one station if you can and the same brand

[Driver72]

Bad gas can just be gas that's a bit less octane than it says.
So if you are in a 91 Octane state, I've seen tests where the Octane is actually 90.7

I don't know the formulation process either, but I suppose like anything else, there are some companies that don't go to certain lengths as others and just do enough to pass the required tests, while others may go much further for a more pure and clean gas. IDK

But it's true about the Octane ratings.
They can be 90.7 and claim 91 Octane.
Other tests I've seen where the 91 Octane gas is actually 91.2

"bad gas" also usually doesn't have any good cleaning agents in the premium either.

[Ruff Rider]

Read this.

http://www.aa1car.com/library/us10325.htm

[Rez90]

Bad gas refers to gas stations not actually selling the fuels they advirtise.

I.E. 93 not actually being 93......causing turbo and high performance engines to knock and not preform to expectation.

A good friend of mine owns a very well known tuning company and he told me that BP and Shell consistantly show the LEAST knock and provide the most power on his dyno.

[bronco]

"Bad Gas" could also mean that ethanol was added to the gas so it could bring the octane # higher....

[CaptChaos]

Stick with the BMW recommended Top Tier vendors and you should be ok.

QuikTrip
Chevron
Conoco
Phillips
76
Shell
Entec Stations
MFA Oil Company
Kwik Trip/Kwik Star
The Somerset Refinery, Inc.
Chevron-Canada
Aloha Petroleum
Tri-Par Oil Company
Shell-Canada
Texaco
Petro-Canada
Sunoco-Canada


http://www.toptiergas.com/

[MBMWTECH]

Bad gas is not B.S. Bmw only recommends premium fuel from a top tier gas station with an ethanol content of 10% or less. Ethanol has become a problem lately - too much ethanol can damage your fuel delivery system.

also some stations have water in their fuel tanks which causes all kinds of problems - i see it almost daily - seems more likely to happen in the winter months.

If you stick with the fuel from a well known and established fuel company yo should be ok - but even they too can get fuel that is substandard.

[vbb]

Where is the list of BMW recommended stations? I appreciate CaptChaos for listing them out, but I'd love to read up on why these particular ones are recommened. Not to be completely cynical, but some of those fuel companies could have given some sort of deal to BMW to appear on their preferred list.

Bottom line is that I want to make sure I'm not harming my car by filling up with Citgo or some other company on those occasions I don't make it to a Shell station.

[Driver72]

Originally Posted by vbb

Where is the list of BMW recommended stations? I appreciate CaptChaos for listing them out, but I'd love to read up on why these particular ones are recommened. Not to be completely cynical, but some of those fuel companies could have given some sort of deal to BMW to appear on their preferred list.

Bottom line is that I want to make sure I'm not harming my car by filling up with Citgo or some other company on those occasions I don't make it to a Shell station.

No deal to BMW from the oil companies.

I think it was BMW, Honda, GM and one or two other companies that decided they wanted to make a list of what they consider "Top Tier" gas companies.
These are gas companies whose gas actually EXCEEDS the standard testing done by the government and so forth.

The list that was provided above are the stations that these car manufacturers (including BMW) concluded had the best gas in their testing.

FYI, the leading gas company Exxon/Mobil is not one of them. And several tuners have shown that in their experience Mobil/Exxon gas has given them less power and caused more issues on tuned cars than say Shell, 76, or Chevron.

[Terry335]

Bad gas is the official BMW excuse when the car isn't running as strong as you'd like.

[O-cha]

All gas in the united states flows through the same pipelines. Gas companies put in say 1000gallons of gas at once end, and then they take out 1000galons at the other end. The gas they get out is NOT the same gas that they put it, it can be gas from ANY of the gas suppliers in the united states.

the pipelines used to be "plugged" between grades of fuel (IE between 87 and 93 octance) but they don't even do this anymore since they found that the gas does not mix together much in transit without them. They simply empty all the 93 octane they can, empty the mix, and then empty the 87 octane.


The difference in gas companies comes in the additives they put in once they take the gas out at a regional pumping station. (this is where it goes onto the trucks for local delivery) Each company has its own special blend of additives.

So the brand of gas doesn't really effect octane, which is what will make your car run wrong in the short term. Now different companies may have different quality control standards, like have checks in place in case a pumping station gives them some mix, but the pumping stations have strict checks of their own.


As for the "top tier" fuels, this is something that was created out of agreement between auto makers and gas companies driven purely by the prospect of profit.

[Bimmer335i07]

Bad gas can also be caused by eating too much Chipotle!

[Driver72]

Originally Posted by O-cha

All gas in the united states flows through the same pipelines. Gas companies put in say 1000gallons of gas at once end, and then they take out 1000galons at the other end. The gas they get out is NOT the same gas that they put it, it can be gas from ANY of the gas suppliers in the united states.

the pipelines used to be "plugged" between grades of fuel (IE between 87 and 93 octance) but they don't even do this anymore since they found that the gas does not mix together much in transit without them. They simply empty all the 93 octane they can, empty the mix, and then empty the 87 octane.


The difference in gas companies comes in the additives they put in once they take the gas out at a regional pumping station. (this is where it goes onto the trucks for local delivery) Each company has its own special blend of additives.

So the brand of gas doesn't really effect octane, which is what will make your car run wrong in the short term. Now different companies may have different quality control standards, like have checks in place in case a pumping station gives them some mix, but the pumping stations have strict checks of their own.


As for the "top tier" fuels, this is something that was created out of agreement between auto makers and gas companies driven purely by the prospect of profit.

So how do you explain the refinery process then?

Down near the LAX airport, Chevron has a refinery, if all the gas is exactly the same, what are they specifically doing at the refineries?

Also, I have read independant tests of gas taken from different gas stations.
In one test they tested like 5 different brands of 91 Octane gas.
They ranged in Octane from 90.7 to 91.2
If all gas was the same and the only difference was the additives, why was there 5 different results from 5 different gas stations?

And how would you explain then how tuners (Like Shiv) who have done countless hours of tuning on thousands of different cars, can show that on certain brands of gas they consistently show lower dyno numbers or have greater issues with tuning than on others?
BTW, both Shiv and Dan Harman (both two very respected tuners of cars like EVO, STI, and BMW 335i) both have stated they've had issues when customers bring in cars with Mobil, CostCo, ATCO and other crappy gas in their tanks.
Both like Shell, 76 and Chevron best.

[ironic]

Originally Posted by Bimmer335i07

Bad gas can also be caused by eating too much Chipotle!

readfirst sentence of op's post haha

[O-cha]

Originally Posted by Driver72

So how do you explain the refinery process then?

Down near the LAX airport, Chevron has a refinery, if all the gas is exactly the same, what are they specifically doing at the refineries?

Umm, I never said all gas was the same, or at least I never meant it the way your read it. Obviously all gas is not the same octane, refineries refine oil into separate octanes. Lets say that chevron refinery makes 1000gallons of 93, they stick it in the pipeline to be sent to Ohio, then they get gas out at ohio. That gas could be gas from BP refineries for all they know, it's very likely it's not gas from their refinery.

Understand now? This is a fact.

Originally Posted by Driver72

Also, I have read independant tests of gas taken from different gas stations.
In one test they tested like 5 different brands of 91 Octane gas.
They ranged in Octane from 90.7 to 91.2
If all gas was the same and the only difference was the additives, why was there 5 different results from 5 different gas stations?

Independent studies are nice and all, but so what? Did they consistently show that shell sold 91.2 octane gas as say safeco sold 90.7? I'm guessing no, they just told you there was variation. The difference is in the additives. Also .5 octane is not exactly a huge variation. Where is this study?

Originally Posted by Driver72

And how would you explain then how tuners (Like Shiv) who have done countless hours of tuning on thousands of different cars, can show that on certain brands of gas they consistently show lower dyno numbers or have greater issues with tuning than on others?
BTW, both Shiv and Dan Harman (both two very respected tuners of cars like EVO, STI, and BMW 335i) both have stated they've had issues when customers bring in cars with Mobil, CostCo, ATCO and other crappy gas in their tanks.
Both like Shell, 76 and Chevron best.

Ask them, I'm just giving you the facts, and facts they are.

[vbb]

Originally Posted by O-cha

All gas in the united states flows through the same pipelines. Gas companies put in say 1000gallons of gas at once end, and then they take out 1000galons at the other end. The gas they get out is NOT the same gas that they put it, it can be gas from ANY of the gas suppliers in the united states.

the pipelines used to be "plugged" between grades of fuel (IE between 87 and 93 octance) but they don't even do this anymore since they found that the gas does not mix together much in transit without them. They simply empty all the 93 octane they can, empty the mix, and then empty the 87 octane.


The difference in gas companies comes in the additives they put in once they take the gas out at a regional pumping station. (this is where it goes onto the trucks for local delivery) Each company has its own special blend of additives.

So the brand of gas doesn't really effect octane, which is what will make your car run wrong in the short term. Now different companies may have different quality control standards, like have checks in place in case a pumping station gives them some mix, but the pumping stations have strict checks of their own.


As for the "top tier" fuels, this is something that was created out of agreement between auto makers and gas companies driven purely by the prospect of profit.

Thanks for this post... this is what I was talking about specifically. I'm not usually big on conspiracy theories, but when car manufacturers release a list of preferred or top tier fuels, a skeptical person would sense collusion in that deal.

So if there is a marked difference between Shell and Exxon of the same octane rating, what evidence of this do we have?

Like Terry said, people throw out the phrase "must have been a bad tank of gas" as if that explains everything. I just don't know what that's really supposed to mean.

[Bimmer335i07]

Originally Posted by ironic

readfirst sentence of op's post haha

Oops. lol! I just read the topic and thought I'd give my $.02.

[Driver72]

Originally Posted by O-cha

Umm, I never said all gas was the same, or at least I never meant it the way your read it. Obviously all gas is not the same octane, refineries refine oil into separate octanes. Lets say that chevron refinery makes 1000gallons of 93, they stick it in the pipeline to be sent to Ohio, then they get gas out at ohio. That gas could be gas from BP refineries for all they know, it's very likely it's not gas from their refinery.

Understand now? This is a fact.




Independent studies are nice and all, but so what? Did they consistently show that shell sold 91.2 octane gas as say safeco sold 90.7? I'm guessing no, they just told you there was variation. The difference is in the additives. Also .5 octane is not exactly a huge variation. Where is this study?




Ask them, I'm just giving you the facts, and facts they are.

Ahh I see.
The study I was referring to I think I read a couple years ago in Sport Compact Car magazine. They hired a gas lab test and posted the results.
I read a similiar type test a few years before that too.
I'm sure they are still out there somewhere.

I agree with the statement that one test with .5 Octane variation between 5 brands of gas is not conclusive.
But what's MORE conclusive to me is having two different tuners that I have met personally tell me in their years of tuning and testing cars that certain gas from certain companies have proven to them that they do better on the dynos and show better results when tuning.
To me that's like have two well known medical doctors tell you to avoid a certain activity or product and use only other certain ones because in both of their experiences the other products have shown to have better results.
I'd go with the products that the two different and well respected doctors advised me to use.

It's not worth it to me to save .06 cents a gallon (or .60-.80 cents on a fill up) to use the cheapo off name brands of gas if it's going to cost me 5-10 rwhp and make my car perform worse and on top of that leave more deposits in my engine because they don't use as good of cleaning agents/additives.

That's all I'm saying.