They do not. Sure the same city where the gas stations are may be from the same place but it may not be from the exact source like tank at the storage facility. Only thing that's the same is the additives.


The same grade of gas from a facility can go to Shell, Conoco, Valero. The only thing that's different is the additive in the gas. And one day that same grade of gas can be different than yesterdays gas.

So get gas where ever you want because at the end of the day it's all different even at the same gas station.

 

daniel01, w/ respect, you forgot to proof read, and you accidentally contradicted yourself. Paragraph 1, last sentence is incorrect, paragraph 2 second sentence is right. - - The petrol is usually from the same terminal, and no report on the petroleum industry has suggested that gas from different storage tanks at the same terminal has different properties.

However, the additives are different, based upon the chemistry the gas company selects.

BTW: This may not hold true for the 2nd-tier gas dealers that buy on the spot market. It's quite possible that if a city has more than one terminal or delivery system, the spot market can yield petrol from different suppliers. The 2nd-tier market generally does not add additional chemical packages. They save $$ you lose!
But that's not how the majors do it, and Shell is one of the majors.

 

I occasionally use shell but i prefer to buy from Valero, its gasoline from the US. Shell, chevron, ect gasoline comes from the middle east. Its my own political issue and Valero is great gasoline.

 

What about Arco?

 

Now you know the secret to "Oxigenated gasoline."

 

Shell is just about the best you can put in your car IMHO. Shell fuels are tested and have been for years in partnership with Ferrari for high performance engines. If you are not using Premium at a Shell station, you may not be getting Shell gas. It depends on whether the station is company owned or not. However, all Shell gas has additives put into it (same as other gasolines) to support a cleaner burning fuel.

I use Shell exclusively but will run Chevron premium about every fourth tank. Always have in every vehicle I've owned. I've NEVER had any engine issues whatsoever.

 

I thought the atmosphere was made of 80% elemental nitrogen gas. ?? But I agree that the nitrogen that they advertise is an non gaseous organic compound which makes up just a very small percentage of the hydrocarbons which make up gasoline.

 

Shell for me, but my auto does hesitate to start when it sits for a few weeks...normal I was told...but if I start it after a few days, n isue, only after long periods of time resting does it do it.....

 

Shell gas user here. I go out of my way to get it. Works great for me.

 

Dad worked in purchasing for one of the big railroads. Diesel, but he got to know the industry. There are only so many refineries, so many gas lines, so many terminals. It is mostly in the additives. And too me, that is more marketing hype than anything else.

I don't buy from unknowns unless on the road and middle of no-where. However, I don't have a favorite. Heck, I fill up at Costco. Cheaper! And no issues over three Corvettes and that many DD's.

 

Arco cost less than Costco.

 

1 - Name brand gas....implied quality
2 - Very busy gas stations...fuel storage/inventory used quicker.
3 - Changing brands at fill ups can be a good thing to reduce each brand's tarnishes.

Nothing wrong with Shell (I use it - In Francisco Bay Area).

If you want a study, do some dyno runs with different brands...I think that would be a waste of resources though.
AND/ OR
Run a tank of each, do a same rpm plug chop and pull a spark plug and compare color/ reside on the porcelain.

 

Typical mix of fact and fiction for a gas thread. Shell’s detergent is a compound that contains the element nitrogen. It’s a very good detergent meeting top tier specs. Other companies meet top tier specs using detergents without nitrogen, so in that respect, “nitrogen enriched” is a marketing gimmick. But having a good detergent that meets top tier specs is not a gimmick. Such fuels do indeed result in measurably cleaner engines.

The old story that all gas comes from the same pipe is one I’ve commented on before. In some areas of the country that’s true. But if you live near water (river or ocean) or near a major refining center (like Houston, Chicago, LA, etc) odds are you actually are getting gas from that company’s refinery. Even if you are in the middle of the country being supplied by pipeline, you still might be getting gas from that company’s refinery, as it is possible to segregate shipments in pipelines. However, regardless of what refinery the gas comes from, it is always true that if the company is advertising its additive package on the pump, you are getting that additive package. Additives are added to the delivery truck. There would be too much legal risk for a company to take a chance on not having an advertised package in the gas.

Ethanol is a controversial and complex topic, but not very relevant to this thread. It does reduce mileage, but the Feds mandate it in several areas of the country, and it should not impact the symptoms being mentioned in this thread one way or the other.

Fresh fuel isn’t very likely a relevant factor either. The only remotely possible link is that as it stands around, there are more chances to get a bit of condensation water in the gas. But that is normally not a problem except during winter storage where cold temps can cause water to condense. And if it did happen, it would be much more likely to be a one shot deal than a continuing problem.

While I wouldn’t say it’s likely, it’s conceivable that you got a bad tank of gas somewhere along the line that led to some quick engine deposits on injectors or valves. If that happened, it should clean itself up with a few to several tanks of top tier gas, including some full throttle acceleration runs.

But overall, I’d agree with some other posters that said the most likely issue is a mechanical problem such as those that others mentioned (fuel pump, fuel filter, injectors, cold engine enrichment programming in the engine computer, idle air control valve, etc).

 

Shell is the best IMO. Its what the top race teams use (MotoGP, F1, etc).. and I trust them to have best detergents.

That said.. I'd definitely try another gas station. Maybe even another brand. Diff brands use different detergents.. and few tanks of Exxon or Chevron could clear up the problems you are having. As others have said, it could all be attributed to the one station you are using has bad/tainted gas.

 

Who

 

Either drain the tank or actually drive the car a couple of weeks to get rid of the old stuff, and then use a gas stabilizer and/or keep the tank 1/4 full so that you're putting in fresh gas more often.

 

 

Valero is owned by Chaves from Venezuela. Not from the USA.

 

I use Shell exclusively in my C6. Use Race Track for the other cars. I filled up my C6 at RT one time and could feel the loss of performance. Car runs great with 76k miles.

OP's problem could be from bad gas from sitting or from water in the stations tank.

 

For gigs try a tank of 87 octane. Back in the 90s I saw lots of cold start drivability issue's caused by fuel. GM had lots of TSBs out on such. I use Chevron and Shell in all my vehicles and get the best mileage from those two. The few times over the last years I had a hesitation on cold start or a judder it was a vehicle issue not a fuel. But there are different blends ,time of year etc that can affect driveability. Try a tank of 87 just to see if any difference.