Want to settle the which gas is better question

[jmkgr1]

Everyone has an opinion as to which brand or unbranded fuel gives you the best bang for you buck. I would like to enlist as many people as possible to help put this matter to rest once and for all. I would ask those of you currently using unbranded fuel exclusively to purchase a branded fuel for 4 tankfulls. Also those of you who stricly buy only branded fuel to try the unbranded fuel for the same 4 tankfulls. Only critirea would be that for the most part you currently only use one brand and that your alternate selection be of the same brand all 4 tankfulls. As well as the mpg we will also be checking the even more important (cpm) cost per mile. Easy enough to do. Thanks for you time.

[SVOboy]

I doubt that will settle much. Over the next four tankfulls I gather temperatures are going to change quite a bit, as well as all the other variables you have. If you really want to settle it rent a dyno/shop for a couple days and go nuts,

[wagonman76]

I have not really noticed any difference. I think the station has to do more with gas quality than the brand. Like there are a few stations around here that sell gas that is either watered down or old or something, me and many people I know have problems with the same ones. Then there was this one time for a couple months or so in 1998 or so when me and all my friends noticed that gas from Holiday station gave us noticeably more power. Maybe they had some sort of mixup.

One thing to check is if the gas you are getting has 10% ethanol or not. Ethanol will generally reduce your power and mpg a bit. Dont know about there, but Michigan used to have to post at every station whether or not you were getting 10% ethanol. Then awhile back they passed a law where they no longer have to disclose what they sell, so Im sure they all use 10% or more now.

[ankit]

Hmm, people seem to think that Sunoco has really good fuel. My dad recently changed the brand of his gas station from Citgo to Sunoco and business has shown to favor Sunoco. Customers also come in and say they buy nothing other than Sunoco because it works best with their vehicle (this is something that nobody ever said about the Citgo fuel).

But as SVO said, it would be pretty hard to test. Way too many variables.

[Brian03cav]

i too hear that sunoco provides a better fuel. personally i like to fill up at the local wawas because in my mind fresh is a good thing, and people are always getting gas there so it must be brought i frequently.

also a gas station (wawa) just opened near me brand new, so i've been filling up there all the time now, figuring all new equipment and tanks and such, my numbers have been good so far, but i havent been testing the switch over as heavily

[Johnny Mullet]

I always run Shell V-Power premium fuel in my car. I was on a road trip one time and got fuel at some local store with no-name pumps. I used the premium grade, but noticed about an hour later the car was "pinging" under load. Either the fuel was not premium grade or the fuel was contaminated.

[bikin' Ed]

Most fuel at no name station comes from the exact same refineries as the brand names. I've even had occaision to see a brand name and an independent station have their tanks filled from the same tanker. Unless you know which refinery produces the fuel you have nothing to compare by.

[groar]

Hi,

My wife and I were using only low/mid-grade diesel. I tried hi-grade and since the half of the 1st tank I felt the difference : the engine was accepting to accelerate under 1500rpm while it didn't before. I'm now at the 4th tank and I can use rpm as low as 1200-1300rpm.

I don't know if it would have made a difference if I didn't changed my driving style at the same moment. This grade change did helped me in my quest as I can now shift up far sooner.

I'm now saving 33% diesel (ie EPA+50%) so I may keep the hi-grade as it's the same cost as mid-grade + low cost additives. The result is that I'm saving "only" 30% of my money (compare to 33% of diesel saving), but my first goal is to save CO2 (see my signature), following Concrete's signature :
"Start where you are - Use what you have - Do what you can.".

IMHO, going from low/mid to high will show a difference rather quickly if you never used it before, or since a long time. Going to low from hi shouldn't show a difference in 4 tanks as it will not be dirty enough to have a performance chance in that time laps.

2 Euro cents...

Denis.

[lunarhighway]

it also depends on the stations installation, contamination in the tanks, like water, temperatures, etc all have a small impact.

i've also heared that it's better to use stations wich are more fequently used as they always have newer gass as older gass might change slightly in constitution.

on the other hand i've also read it's not a good idea to fill up right after a station has been refuled as the new gass might have stirred up dirt particle from the bottom of the tanks that have become suspended in the fuel.

finally there have been cases over here in the past of station owners mixing cheaper lower octane fuel with higher octane fuel and selling it as the later...

i don't have any strong evidence of any of this and what the impact on your actual FE might be... but in theory all these things could create variations withing the same brand.

useing on road testing will introduce even more variables so unless the differences are really big i doubt anything other than controlled lab testing could reveal the true difference in fuels.

[ATaylorRacing]

I can only speak of 92-93 octane fuels used in my 285 hp SRT4 Neon.
In all cases the 93 allows more boost than 92 or 91.

My best boost comes from BP and Marathon. Next best power comes from Speedway and Shell.

In the late 80s and 90s Marathon was the provider for Speedway, but now their oct differs...don't know what is up with that.

Any gas with a 10% mix I stay away from except in emergencies....they cost the same around here but it kills my cars power and FE...even my 3 cyl Metro gets worse FE with it.

Many stations have troubles with rain water getting into their tanks, then into your car. A dealership that sponsored my cars would have at least 5 cases a week where people with their Chrysler products could barely make it in or had to be towed in....in every case they had filled up at a no name gas station 13 miles away....a sample of the fuel in a clear glass would show the destinct settling of the water and fuel! Eventually those tanks were repaired.

In the late 70s I had gotten out of the Army and found a job at Monkey (Montgomery) Wards....the mgr of their "gas" station was always amazed that they would sell more a month than the tanks would hold!