Ok, could someone please explain to me the differences in gas? Some of the smaller name companies sell gas 5 to 10 cents a gallon cheaper than the larger oil companies. is there a difference in the quality of the product? don

 

Company names will help. Many companies sell gas that was all made in the same place. Region, local economy, traffic...these all have a lot to do with cost of gas.

 

They try and undercut the big boys to get business. They then make very little profit on a gallon of gas.

Used to be that way up here in Canada until the big Oil companies put the small independents out of business. Now the big oil companies change the prices the same across an area effectively ripping everyone off in unison

 

A couple of weeks ago I went to my usual Exxon station with the Vette and the regular attendant that I always see there tells me that when the gas tanker comes to fill the tanks in the ground they only open one cover in the ground. He says in the 4 years he's been there they never opened the other covers to fill the station tanks. All the gas there is the same, 87-89-93 octane, it's just one big tank. It has to at least meet the min requirements posted on the pumps and says that the gas they deliver is 94 octane no matter which grade you choose. I tested this out and got 87 octane one day and you know what, my engine still ran the same without pinging, and I have it setup on the verge of pinging with the timing. Just thought I'd share that with you all.

 

I can tell you for a fact that this is not the case where I live and work. I am an engineer for a car company and we were seeing some "funnies" in our air/fuel ratios with known test fuels so we went to a local gas station and bought different fuels there for comparison. With these, we were able to replicate our issues and then we had the fuels analyzed. The results showed that there are definitely certain levels of measure for various fuel characteristics and I have to imagine that these are regulated by some facet of the fuel legislation. Of course, whether or not these are ALWAYS followed is probably another story (ie. I'm sure there are MANY stations around where you get "GAS," regardless of what octane rating you THINK you're actually getting.) But I can tell you that there certainly are different fuels and they are sold as different products, at least at a couple local stations near me.

 

the blend if gasoline varies accross the nation this link is to a map of government fuel blends across the nation
http://www.exxon.com/USA-English/GFM...soline_Map.pdf
but there are parts of the country that have gasoline with 10% or more oxygenates (ex:ethanol) in the gasoline. there may also be a few less than honest gas stations that cut the gas with ethanol or mix low grade with thier high test gas.

the additive or deposit cleaning additives also vary from brand to brand, a top tier gasoline http://www.toptiergas.com/
has a higher level of cleaning additives than the government mandated minimum level.

as for the gasoline of today vs the leaded gasoline of days past, this quote is from a fuel scientist from one of the major gasoline suppliers to a question i had on the changes in gasoline.
"The differences between today's fuels and leaded fuels are many. Burn time is a clear one, so is distillation profile. But it actually goes deeper than that. You have density differences as well as flow changes. The composition of the fuel at a molecular level is very different now, so it even flows differently."
to me this helps explain why we are having to recurve the ignition spark advance curves and change the jetting - air/fuel mixture curves of a carbretor equipped corvette.

I do not see how anyone could sell a new carburetor or even tune a carburetor equipped corvette to run its best in every part of the country when the gasoline quality and the % of oxygenates in the gasoilne can very by so much. being here in California i get to see a lot of fuel related driveabilty problems. I A feed-back computer controlled fuel injected engine at least has a on-board tuner to make some of the needed tuning changes for the gasoine being used but i still prefer a carbureted engine!

i hope this helps Henry @ olescarb

 

US octane ratings being an average of the Research Octane Number and Motor Octane Number for a given gas, (RON+MON)/2, the cost and quality of the gasoline in question depends on what type of method was used to obtain a given octane rating. Since RON is less expensive to boost than MON, the higher the RON is than the MON the cheaper the production costs. Unfortunately, the larger the spread between a higher RON and a lower MON (you won't likely ever see it the other way around at the pump) the poorer in quality is the gas, as it is Motor octane that really counts in the real world under your hood.

That's not to say that name brand fuels are always better, however, as several of the big ones have been found lacking, regardless of whatever additive packages are on board. I'm not going to point any fingers, but you can see Vizard's "How to Build Horsepower, Vol. 2, pg 36 for more on this, as he's done the homework.


edit - BTW, oxygenated fuel sucks. I always expect to see about a 10-15% drop in economy (and likely performance, as well) when the summer season rolls around where I am.

 

OK, now you talking my language....
low grade mid grade higrade...

Mid grade is a blend of high and low...
the same truck can haul all
grades...

I work for the 4th largest XOM dealer in the country...
we sell fuel.. and lots of it....
(I"m the Network and Systems admin)

if I can add to this conversation I will be glad to...

 

what i was wondering if there is any difference if i go to a no name independent and buy gas thats the same octane rating but 5 cents a gallon less than the major guys in the market like exxon. don

 

It is all blending and it all comes from the same tank at the refinery. There is no brand difference so people who boycott Exxon stations are foolish. They are buying the same gas at Citgo.

From another forum:
And:

 

The number one supplier of OIL TO THE USA is now Canada
and still the gas is a lot more expensive in Canada,
Comes out to $4:00 a Gallon in Canada

 

Too easy. Gasoline taxes are higher in Canada (and Europe). Got to pay for all those social programs somehow.

 

What about gasoline with Ethanol? Is it harmful to to our old "classic" engines or rubber fuel lines and components? A Hess Station nearby has stickers all over their pumps now saying their gas is now blended with 10% or less Ethanol. Not wanting to take a chance and cause some new problem I passed on it and went elsewhere. Can anybody please share info on whether Ethanol blended gas is ok or bad news for an old L-48, with an original Quadrajet? Thanks.

 

Hellllooooo!!! Exxon and Citgo each have their own refineries, genius!!! Now if you would have said Exxon and Walmart, you may have been right,

And as to the guy who said the tanker truck only fills one tank in his state.....Are you friggin on drugs???

 

I'm sorry, that sounds like the biggest bunch of I've ever heard. No offense, but remember you did talk to a gas station attendant. Why would a gas station sell 94 octane at 87 octane price? Because they are too lazy to order all three?

As far as ethanol, I can't really think of a problem. If you think about it, all you do is lose the power you'd get from a hydrocarbon chain. Instead of breaking those carbon-carbon bonds in a 8-carbon compound, you're now breaking the bonds of a weaker C2H5OH compound. Maybe someone else can think of a problem, but thats the only problem I see: less power output. Anyone?

 

I've heard complaints from boat owners in other states of water related problems when their state went to Ethanol blends, hence more problems with a humid environment where the motor is rarely run. Not sure it is a problem for a garage kept engine that is run frequently.

 

Don't forget to note there is a minimum MON, last I heard it was 82.5. So you're not going to have a huge spread as you might be suggesting. The MON does mean more though here in the forum though because of the hi-perf engine, since MON measures at high speeds and temps. But then again you base your choice of gasoline based on your compression and get it to not ping. So by that you've already removed this MON/RON factor. If it doesn't ping, you got enough iso-octane

 

I went to Chevron a couple of months ago to fill up my boat before I put it up for the winter. I filled it up with the high octane because it seems to keep better over the winter and the engine runs better on it. Anyway, 23 gallons later, it overflowed a little and the gas stank and smelled like it does in old car in the junkyard. Guess the high price had killed their sales of the high octane and it wasnt getting cycled through like normal. I bitched to the station owner and he was sympathetic when he smelled it, said he was going to contact the distributor, I would be hearing from them. Yeah right.
not alot to do with this thread but I feel better!!

 

Yeah , I asked him a couple times "are you sure about that?" and he said "yeah, I've only ever seen them open the one cover when they come". Maybe because most people just get regular and that's what they are filling every time they come, Idk. I really don't care as long as my engine can run on the cheapest gas without pinging.

 

If your rubber fittings and gaskets are original, you'll eventually have problems since the ethanol will eat into those. It's not really too bad with E10 though. Many new hoses, o-rings and gaskets are labeled as ethanol resistant.

Yeah - sounded fishy to me too. Why would anyone sell the expensive stuff for the low price.