No-Name Gas for My 350Z ?

Depending on where you live, chances are it all came up the same pipe.

The fuel is delivered up the same pipe, but the additives put into the fuel at each different supplier modify the fuel somewhat. If you are concerned about the rising ocst of fuel, your best course for economizing is to ensure that your tires are properly inflated, check them at least once a week. A difference of 3 PSI lower than nominal can lead to increased road friction and thus a reduction in fuel economy.

rtt

nothing will happen. they all are governed... so they cant sell water with some gas in it. don't worry.

From the way you speak it doesn't sound like a permanent thing anyway.

I doubt if there's much if any difference when concerning gas milage. I have noticed a slight difference when using premium from Shell vs Chevron or 76. With the Shell premium I could hear a very slight amount of pinging in third gear when just slightly accelerating. I could only notice it under light acceleration. Now this is with a '90 300ZX. I do remember years back I also noticed a slight roughness at idle with my motorcycle when using Shell premium. I just seem to have bad luck with Shell for my higher performance vehicles. No problem when using their regular in my 4-Runner.

Gas is gas. For any given octane grade, it all comes out of the same tank at the pipeline terminal. The delivery trucks for all the brands just line up and fill from that same tank.

The name brands put an additive package into the delivery tanker as it fills up from the big tank. This is a small packet, about the size of a Kool Aid package, that they add to the 2,000 or so gallons of generic fuel being loaded into the delivery truck. This is the *only* difference between brands.

The additive package is mostly a detergent, and neither adds nor subtracts from fuel performance, which is determined by the octane rating. The detergent can theoretically help keep injectors clean, but it is present is such a small quantity that it really can't do much at all. It is mostly something for the brand name advertising guys to hang their hats on.

It is more important to buy fuel from a dealer who does a large volume business. That'll help to avoid getting stale gas, or gas with water in it from condensation. Around here, that means buying from a busy QuikTrip or Racetrac station, the two biggest discount fuel vendors in this area.

The QuikTrip where I buy gas for my 350Z is 9 cents a gallon cheaper for 93 octane than the brand name BP station is charging for 91 octane. The Z *can* tell the difference between 93 octane and 91 octane (the ECU learns it can run more spark advance with the higher octane fuel). So I get more performance for less cost by buying from the discount gas station.

Gary

The only really garbage gas in our area is Quicktrip. I have an old 85 mitsubishi pickup truck with 8.8:1 comp and it rattles on Quicktrip premium! Runs fine even on regular from anywhere else. We had a customer that used their gas one tankful in a 93RX-7 with a fresh engine from mazda and it blew an apex seal out the exhaust port. Quicktrip did pay for the engine, you might not be so lucky. I wouldn't put their gas in my lawnmower but it is like $0.10 a gallon cheaper. Seems silly to me to try to save a dollar a tankful on a car with a $10,000 engine. YMMV of course.

If you believe your local QuikTrip station is selling adulterated gas, call the GA Dept of Agriculture, (404) 656-3605, and they'll send someone out to pull a sample and test it. By law, it has to meet the octane requirements posted on the pump, and must not contain undisclosed adulterants. They *will* close a station down right then and there if it is found to be selling adulterated or mislabeled gas.

If you are under the impression that the gas sold by QuikTrip, or any of the other discount service station chains, comes from a different source than that sold by BP, Chevron, Shell, etc, then drive over to Doraville and watch the tankers being filled at Colonial Pipeline. All the delivery trucks for all the brands will be filling up from the *same* million gallon tanks.

There is no relationship between a name brand station and a name brand refinery. It has been a *long* time (at least 25 years) since pipeline companies segregated fuel by brand source (back in the days when Amoco white really was different because it contained no lead, now they all contain no lead, and gasoline has become a generic commodity).

Colonial's fuel buyers buy fuel week by week from whichever refinery offers them the best price or availability. One week it might be a BP refinery, the next a Shell refinery, the next a Marathon refinery, etc. It all gets pumped into the same million gallon tanks at the terminal, segregated only by octane rating.

The service stations (through their distributors) all buy their gas from Colonial, and take whatever is in the big tank holding gas with the octane rating they need for that load. They add their additive package right there as the tanker is filling. The additive packages look like Kool Aid packets.

The amount of additive, basically detergent, in each 2,000 gallon load is very small, one or two packets. Many times a tanker may be filled with no additive, because the driver forgot to check if he had enough packets to cover the runs he was to make that day. Those loads get delivered to stations without the brand specific additives. No one can really tell the difference since the amounts are so small, and any effects take long term usage of fuel without detergents to become noticable.

Note that the EPA now mandates a difference in the volatility and the MTBE and/or methanol content (oxygenates) of summer and winter blends of gasoline sold in the Atlanta area. Colonial's fuel buyers take care of that. The distributors and service stations have no say. They all take what Colonial gives them, and the EPA monitors Colonial to make sure they're giving them the right thing for the season.

The name on the sign out front of a service station doesn't mean anything with respect to the quality of gas being sold there. Only the Dept of Agriculture labels on the pumps can tell you the octane rating of the gas you buy. Everybody is getting the same stuff out of the same million gallon tanks over at Colonial. Gas of any given octane rating is gas.

Now it is possible that a delivery truck may put the wrong stuff in the wrong tank at a service station, and it is possible that low volume stations may get water in the gas from condensation, but those sorts of errors are equally likely regardless of whose name is out front on the sign.

(If there is fraud, the GA Dept of Agriculture will be all over them as soon as they conduct a test, which they do routinely at every station at least every 6 months, or sooner if there is a consumer complaint.)

Note that while this info is Atlanta area specific, because my next door neighbor has worked at Colonial for 35 years and explained it all to me in great detail, the same thing happens elsewhere, just the names of the companies may be different. This is industry wide practice in the modern era of EPA mandated fuel standards.

Gary

Dude I LIVE in Doraville and know people who work at the tank farms. All I know is the gas they sell at the quicktrips around here pings in any car I've used it in that doesn't have knock sensors to kill timing to stop it. Maybe you're just driving a car that doesn't ping on that garbage because it has a knock sensor?

Then explain why my truck pings on quicktrip premium but doesn't on other people's regular?

Sounds like the people who claim an oil filter is an oil filter etc etc.

Talk to the people you know who work at Colonial. Ask them whether all the brands fill from the same tanks or not. If they tell you that QuikTrip gets its gas from a separate tank with a lower octane rating, then I'll ask my neighbor to invite you over there and let you *watch* the tankers being filled as I have done.

Since there is a 16 point spread in octane numbers there (regular 87, premium

Now that's just silly. Different brands of oil filter are manufactured in different plants using different construction techniques. Oil filters don't all come out of the same distributor tank, gas does.

Gary

Well if all of the gas comes from the same tank then Mobil does not put 93 octane in their 93 octane tanks. I used Mobil in my 300z since the first day I had the car. The compression of my car is 10.5 to 1 and for a while the car ran great then after about a year or two the car ran . . . a little off. Their was the slightest hint of pinging at light throttle settings. Roll into the throttle the pinging would increase then stop as if the timing was back off, the car would accelerate but felt weak. I was sure I bought

Of course they are.. Doesn't mean they put 100% premium in the premium tanks or that their additives are bad etc. I've never seen or heard of anyone around here testing the octane of the fuel in the pumps, only that the pump measures the product correctly.

Nope it's only QT gas that causes the problem so I stopped buying it. I'm not the only person who has complained about it. Here's another one for ya, we get people come in for failed EMI due to high nox, we drain QT gas out and put in someone elses and the car passes... Nox is related to detonation and cylider pressures so something is going on, maybe the additives they use cause this? Because of the above I recomend using -anything- besides QT, you're welcome to use it if you don't think there is anything substandard about their products.

Like I said something is going on, maybe the aditives they use can cause this or they are "mixing" something else in? I realise it all comes through the same pipe but I've experienced that cars react differently to gasoline from different stations and brands. My old Z (77, early head with flat top pistons) seems to run best on some of the cheaper stations so I know it's not the "It's better because I paid more" thing.

The state inspectors are supposed to do a specific gravity test when they check pump delivery. That'll show if the wrong grade is being dispensed. They also do a field test for water. Tanker drivers do sometimes make mistakes, and put the wrong product in the wrong tank. Tanks also can get water in them. This is something the inspectors are trained to catch.

They usually only send samples back to the state fuels lab for a random sample of stations since they all get their fuel from the same source, and the EPA is watching Colonial. But the state will lab test if there is a consumer complaint about the fuel quality of a particular station. The state lab follows SAE procedures to determine octane rating.

Call Kurt Williams, (404) 363-7597, and ask him about this. He is the head chemist of the state fuels lab.

Gary

Or buy my gas elsewhere when I find something that seems substandard. :-)