Brands of Gasoline = Actual Difference
 

First off, I had always been raised with the "gas is gas" mentality and that premium is a waste, obviously we know why our cars require premium.

When doing research a while back (before I got my Z) I came across all of this information about top tier gasolines, etc, "there truly is a difference" "there is ABSOLUTELY no difference"...I'm sure the battle will wage until the last drop of oil is squeezed from the earth.

I've always ran Shell V-Power in my Z because it's my understanding that it's the only premium fuel on the market that an F1 engine will run on - period. I've never had an issue with it.

Yesterday, I found myself in a very rough spot, I've recently moved and found myself lost and my fuel (which was already low) emptying itself...to the point that when I actually pulled up to the pump all orange lights on the fuel indicator were off. We've all got lost, still feel like an idiot, I know.

Long story short, the gas station was a Kroger gas station, I only put a small amount of fuel in to cover myself (about 2.5 gallons) and was honestly a little frightened to do so because of my Shell loyalty, but had no options.

Fired her up - instant pinging, idle dips all over the place...driving felt like there was turbo lag at times and she's all N/A.

Whatever your opinions on fuel quality, I'm just throwing this out there as a personal experience. On longer trips I've had to put in fuel from Marathon, BP, and even Speedway and never had any noticeable issues...my pesonal word of warning - STAY AWAY FROM CUT RATE FUEL AT ALL COSTS

Fuel is all the same (comes from the same refineries), it is additives that are different.

In theory top tier fuels are more closely regulated for impurities/level of detergents, and thus quality should be more consistent but you can get bad fuel anywhere.

Top Tier Gasoline

even if it's a major brand gas station, if that station is prone to flooding or not very well maintained the fuel in there can be bad.

that said i only use 2 gas stations. one in a rich neighborhood where a lot more cars run premium fuel, and another station that recently was renovated and got new tanks installed.

on my dd, i just go to this nice cheepo station where they've been serving good fuel for yrs.

That is another factor, turn over the fuel.
If you go to a Kroger or Wal-Mart station most people filling up are getting the cheapest fuel at the pump, meaning the higher octanes sit for months at a time.

that is solid advice from the Ken. turn over, location, and storage container age all matter.

in a pinch fuel is fuel as you said but in the long run... yea... not the same.

if you had to get mid end gas maybe try adding some octane booster to help until you can find a 91+ station?

BTW, I missed your first comment: Octane needs are a very real issue -- "premium" is only a waste if your engine is tuned to operate safely on a lower octane...

Anyway, the idea is "better regulated" vs. "worse regulated"; its not simply "good" vs "bad" with perfect precision across stations and pumps.

Also, did you use lower than 91 AKI? If so, no wonder you were pinging under load --that's not Kroger's fault.

In racing applications, you are typically working with very exotic (i.e., special additives, specific fuel densities, etc), high octane fuel blends... I dunno about Shell pump gas.

I will say that fuel quality can fluctuate wildly from station to station, but its not because of the brand of fuel its for reasons mentioned above like how long has the fuel been sitting, are the tanks above ground.. etc.

^^^ this. I was super low on gas and had to pull in to a mom and pop store. Thank god they had some octane booster on the shelf!

Is ARCO top tier or discount brand. I assume top tier, but it is the cheapest in my area.

ARCO is Top Tier

TOP TIER Gasoline Retailers:


USA
76 Stations
Aloha Petroleum
ARCO
Beacon
BP
Chevron
Conoco
Costco Wholesale
CountryMark
Diamond Shamrock
Entec Stations
Express Convenience Centers
Exxon
Hawaii Fueling Network (HFN)
Holiday Stationstores
Kwik Trip / Kwik Star
MFA Oil Co.
Mobil
Ohana Fuels
Phillips 66
QuikTrip
Road Ranger
Shamrock
Shell
Sinclair
Suncor Energy Inc
SuperAmerica
Texaco
Tri-Par Oil Co.
Valero

Canada
Chevron Canada
CO-OP
Costco Wholesale
Esso
Petro-Canada
Shell Canada
Tempo

Puerto Rico
Puma Energy Caribe, LLC
Shell

I put 93 Octane in which is the premium around here...very interesting concepts above though...it was definitely in an area where most of the pumps read 1 or 2 bucks of regular...didn't give the consideration to the stale gas/storage container age and turnover. I was pretty shocked with the pings, idle dips, and decrease of engine response time.

Since I put a small amount in, I'm going to simply attempt to burn the remainder of that fuel, put a small amount of my regular station stuff in, burn that off for a few cycles, and then fill it up...I don't want that stuff lingering/diluting "the good stuff."

I use Costco gas whenever I can, no issues.

Just for fun since we're on the topic

https://www.youtube.com/watch?v=zubM2PsBJIU

Also, since we're on the subject, has anyone experimented with octane boosters on top of 93 grade...the ones that promise an octane level of 104etc...I try to keep additives to a minimum (Seafoam, Occasionally a Lucas product that I've used in the past and have noticed results, and Risoline Fuel Treatment OCCASIONALLY just to make sure that I'm keeping carbon to the minimum that I can)...any actual performance results from these small bottles? Or is it all hype?

i used to only fill up at station A and would never go anywhere else, but it's all the same. i pass the same amount of miles with a tank wherever i fill up. i usually fill up at QT by the house now since it's on the way.

I use only shell, apart form the odd time I've had to get a few gallons to get to a shell, and I've gone through over 500 full tanks of gas now, no problems, always about the same mileage. I have seen it, friends of mine, who buy "the cheap gas", and they told me how much that save buying gas there...I told them to fill up at a good gas station and see what they get for mileage...they got about 150 kms more on a tank, they haven't been back for the cheap gas.

As far as the additives go I know alot of people say they are useless and dont do anything. But I have seen first hand through tuning and using knock headphones on these cars that it does help you. Now this is a boosted car that I am tuning right to edge of knock. But I have tuned it, filled up and had it knock, threw some additive in and the knock went away.

Again its just what I have seen/heard personally. I know many people will disagree.

Loyal to no gas station, only gas prices!!! QT and Racetrack usually have the best prices here so it's always one of those.

:iagree: :rofl2:

This actually works?

http://img.photobucket.com/albums/v2...f.png~original

:rofl2::rofl2:

RE: Shell V-power... uh, okay. Although that is far from a controlled study, if the octane rating is the same, and the results are genuine, then the differences are likely due to the additives. If the engine is tuned for a higher octane, unless it was re-tuned, I call BS on the whole thing.

If tuned for 93 AKI, we wouldn't expect much worse results from another 93 AKI fuel...

In any case, Shell is clearly a sponsor for them, so take that with a pinch of salt. Likewise, Sunnoco sponsors NASCAR, hence all the hype there...

RE: Octane Boosters -- I've seen a few lab test shoot outs of various octane boosters -- I believe there's one by Torco that actually is found to raise it about a full AKI point (RON+MON/2), but most of those additives (104 Octane boost, et al) barely budge it a fraction of a point.

It's hard to say what was wrong with the gas you got (water? lower than claimed AKI?), but if you can find a Sunocco with 100 AKI pump gas (only mentioned because I know they have that at some stations -- another brand of that high an octane would be fine if you can find it), a few gallons of that shouldn't hurt, and will help ensure the fuel in the tank is closer to the octane rating needed.

You can find charts on octane blending if you google it to give you an idea how much you need to add.

If it's water in the fuel, you could try adding some Heet (methanol) or toulene to suck it up.

Anyway, unless you are tuned for it, there's no need to go higher than 93. I know of zero evidence that the ECU will allow more advance without tuning just because of a higher AKI. It might help if you were running on the ragged edge on a hot day on the track to stave off incipient knock, but for DD, don't expect any real improvement.

No idea on Risoline -- never heard of it.

EDIT: Looks like it has some alcohol to absorb water. I'm guessing that also helps provide the "stabilizing" action? The alcohol probably also nudges up the octane.

i think that because we are using 93 oct it's sitting in the gas station tanks longer no matter what since most cars don't need it. most people and their cars only need the lower oct so why waste the $$. maybe the people stopping at walmart/costcos go there for the cheap prices but get the high oct since it's also cheaper than most other places. hopefully because that's what i do, get the high 93 oct at the cheaper places.

There are a ton of BMWs around my area, I would hope they are using premium. I'm not worried about gas sitting.

Came across this article...once again, some will always say "gas is gas"...but I simply don't believe it...

All Fuels Are Not Created Equal - Technologue - Motor Trend

And the Shell F1 video is just fun...I like to joke around with people if they ever ask about my Z and say that it uses the same fuel that propels an F1 car...and then of course explain

I use Shell or BP. After years of using premium, these seem to work the best. You notice it more on turbo cars when you get spark knock (detonation). As far as injector cleaners, BG 44K is the only one that works. Seafoam and all the other stuff is junk. Doesn't work. Octane boosters are worthless. Just my .02.

Kroger, at least in Ga, uses BP gas. Regular octane is refilled daily. High octane at least once or twice a week.

OP you must have let the tank run too low and have issues as a result

In the 11 years I have owned various VQ engines I have never had a problem with any particulat premium brand. I have run them all and will say that we as enthusiasts tend to over think fuel

Your paranoia with off-brand premium is unfounded and will only get you in trouble driving around aimlessly

P.s download the "Gas buddy" app so this doesn't happen again

I wasn't aware of that 0.o

I only use Shell, 93 Vpower ( Been using it for years 15+) Will if need be use Sunoco but and always use the same station -if I can-.. The octane booster the only on I used is Turbo 108
Blue Magic/16 oz. Turbo 108 Octane Boost NA30 at AutoZone.com

I have no way of testing it other the a years ago I did my own thing with my old Monte SS. I hadn't started using this stuff yet, I took the intake mani off and changed it and the carb, notice a lot of yellow deposits and build up inside the carb and intake runners. I ran this octane boost for 8 weeks took of the carb and mani again and could eat off it.

I use Shell, Valero, Chevron/Texaco and now Murphys (by Walmart) with no issues with any of them. I dont care where I go and I buy the cheapest I can find.

I think another member on here (BGTV8?) originally posted this, but FWIW, here are some independent lab test results on changes in octane from various additives. I'll see if I can find something more authoritative, but for now, this is seemingly impartial and informative.

Note that they are going by RON, not AKI (RON+MON/2). TO get an approximate, multiply the RON by .95 (e.g., 96 RON is approximately 91 AKI).

http://www.fueltechexperts.com/2008/...which-is-best/

:iagree: Every 4th or 5th tank I put in Chevron premium (I'm a believer in Techroline for keeping the injectors clean).

Lower Octanes
 

Lower Octanes are used in higher elevations, because of the thinner air. Something to do with the fuel/oxygen ratio. I read this on Shell's site, after being use to 93 octane here is se texas, then being able to get only 91 in the mountains.

The lower air pressure as you start climbing several 1000' above sea level reduces internal temps and also effective ("dynamic", I think...) compression, so less likely to autoignite the fuel.

Go up high enough, and the lower oxygen levels also mean you need less fuel to hit AFR/Lambda targets.

Of course, you also lose power.

Octane is just one of the many factors that helps control unintended combustion events (reflects resistance to "auto-ignition"), which result in knock (the sound made from an un-timed combustion event).

The force from untimed combustion events can break pistons (ring lands in particular tend to be weak points -- enough force produced on a timed even can do that too, BTW), break loose rods from their bearings (i.e., "spinning a rod"), or if you have a high enough temp produced from a flame kernel on the piston crown, it will look like someone took a welding torch to it and just melted through the center of the crown (google it -- it's kind of horrifying! Much nastier looking than a shattered piston.)

Extra fuel (i.e., "running rich") also helps cool down the piston -- that extra fuel is "wasted" to quench hot spots.

What causes fuel to ignite out of time (i.e., not during a planned spark event)? Too much in-cylinder heat (mitigated somewhat via clever valve timing or freer flowing head and EM as well as lowered intake valve temps -- that's part of why intercoolers or W/I is great on boosted engines), higher cylinder pressure, flame kernels that don't disperse quickly enough for various reasons (e.g., "hotspots" on the piston crown), uhh... I'm sure I'm forgetting something, but that's the gist of it, at least based on my modest understanding of engine tuning...

Me too. I buy when I need to and at whichever gas station is open. Did that and put up 156k miles on my Prelude, never had any problems with it, my 350Z and any other car I drove.

Putting select gasoline and thinking your car drives better for it is like buying the most expensive golf clubs and thinking your golf game will be like Tiger Woods.

It's why "branding" works. It falsely convinces people that buying their product makes you better.

BINGO!!!!!!!!! :iagree:

The only gas I will never buy is Arco. I purchased it once back when I had my SRT4 and my car ran like **** for the entire tank of that watered down POS. It could have been that particular gas station (and it was when gas was really expensive and ARCO is almost always $1.00 cheaper than any other station) - so the sheer volume could have contributed to its shittiness. Thankfully you don't see too many Arco's around here in Phoenix.

QT & Fry's are where I typically fill up. Fry's has gas points that I steal from my parents. :icon17: