Ok, this is probably a stupid question, but I am wondering about certain pumps at gas stations. Specifically the ones that have one pump for all 3 octanes of fuel. How do those work exactly? I mean, say I go to fill up with 91 octane, but the person in front of me just bought 85 octane pee water. Wouldn't there still be some of that 85 left in the house that would go in my car? I know it wouldn't be serious to my car if I put some in along with the 91, but if I'm paying for 91, I want all 91. Sorry if this is retarded, I was just kind of curious about it.
Gas Station Question
- Thread starter White92
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Yellow Rose
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Not A Problem
Gas stations have three tanks - one for 87, 91, 93 octane.
In the old days it didn't matter because the volume of 87 octane that remains in the hose is not enought to even put a dent in the 18 gallons of 93 octane you just put in the tank. Alas, then came the tree-hugging environmentalists and oxygenated fuels were invented to reduce emissions. The contoversial additive was MTBE. MTBE in one octane does not behave the same as in other octanes. So here is how your concern is addressed.
Three underground tanks feed one pump. At the pump, there is a dedicated recycle line to each of the three tanks. Because the pump's electronics are smart enough to know what octane the previous motorist used, it can correct for the next motorist.
It is OK to put higher octane into lower octane but not the other way around.
Motorists A fills with 87. Motorists B arrives at the same pump and begins filling with 93. Although the handle is pulled and you can hear the pump running, there is a few second delay in hearing the gasoline swooshing into the tank. Why? There is a three-way divert valve that sends the first few pints of gasoline back to the underground tank that motorists A just filled from. After the timer times out, pure 93 octane is now flowing into your tank.
Motorist B filled with 93 octane. Motorist C wants to fill with 87 or 91 octane. Because it is ok to "spill" a few pints of higher octane gasoline into lower octane gasoline, the three-way divert valve does nothing and gasoline enters your tank the instant the handle is squeezed. So you get a very miniscule increase of octane from motorists B's previous visit.
Gas stations have three tanks - one for 87, 91, 93 octane.
In the old days it didn't matter because the volume of 87 octane that remains in the hose is not enought to even put a dent in the 18 gallons of 93 octane you just put in the tank. Alas, then came the tree-hugging environmentalists and oxygenated fuels were invented to reduce emissions. The contoversial additive was MTBE. MTBE in one octane does not behave the same as in other octanes. So here is how your concern is addressed.
Three underground tanks feed one pump. At the pump, there is a dedicated recycle line to each of the three tanks. Because the pump's electronics are smart enough to know what octane the previous motorist used, it can correct for the next motorist.
It is OK to put higher octane into lower octane but not the other way around.
Motorists A fills with 87. Motorists B arrives at the same pump and begins filling with 93. Although the handle is pulled and you can hear the pump running, there is a few second delay in hearing the gasoline swooshing into the tank. Why? There is a three-way divert valve that sends the first few pints of gasoline back to the underground tank that motorists A just filled from. After the timer times out, pure 93 octane is now flowing into your tank.
Motorist B filled with 93 octane. Motorist C wants to fill with 87 or 91 octane. Because it is ok to "spill" a few pints of higher octane gasoline into lower octane gasoline, the three-way divert valve does nothing and gasoline enters your tank the instant the handle is squeezed. So you get a very miniscule increase of octane from motorists B's previous visit.
Re: Not A Problem
In the old days it was possible for some kid out of money to pull-up to a gas station that was closed and put the nozzle in the tank and then lift the hose to get any remaining fuel out of the hose and into their tank. Not so now because of the reason Andy states. I actually found my way home a few times by this old method.AndyVecsey said:
Re: Not A Problem
Where did you come up with this story? Are you smoking left handed cigs or what?AndyVecsey said:
THE ANSWER IS BULL SHITThis is what pumps your gas and is in each product tank.White92 said:
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i used to work at a gas station when i was a youngin...well lemme tell ya something !!!
I dont know about any where else but in NYC there is a thing called a tip over.Now i worked at an independantly owned gas station, never worked for any brand name gas station.OK back to the tip over.....usaually the manager or who ever orders the gas would take readings of the tanks to see roughly how much gas we had.Then they would tally up what we were getting short on and place a order for a gas delivery. In many cases when there was left over regular unleaded gas aka 89 octane they would ask the driver to do what is known as a tip over...the price of the tip over would be determined by the driver.I dont recall how much was the goin rate but lets just say for example there was a 100 gallons of 89 left over...he would dump it into the 93 tank for 10 cents on the gallon.It seemed to be common practice and the driver didnt think twice about it.Occasionaly inspectors would come around and take samples of the gas and if it fell below the rated octane or contained water,there would be a fine imposed.
I dont know about any where else but in NYC there is a thing called a tip over.Now i worked at an independantly owned gas station, never worked for any brand name gas station.OK back to the tip over.....usaually the manager or who ever orders the gas would take readings of the tanks to see roughly how much gas we had.Then they would tally up what we were getting short on and place a order for a gas delivery. In many cases when there was left over regular unleaded gas aka 89 octane they would ask the driver to do what is known as a tip over...the price of the tip over would be determined by the driver.I dont recall how much was the goin rate but lets just say for example there was a 100 gallons of 89 left over...he would dump it into the 93 tank for 10 cents on the gallon.It seemed to be common practice and the driver didnt think twice about it.Occasionaly inspectors would come around and take samples of the gas and if it fell below the rated octane or contained water,there would be a fine imposed.
I doubt if you should worry about tipover at Branded outlets because the gas has a tracer in it and is checked often for co-mingling also the state aguculture commission checks octane monthly. Not worth the chance of loosing a contract or 1000.00 fine.Eric5273 said:
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White92 said:
Sorry to contradict you on this one, but the 85 octane gasoline is actually more "explosive" than your 91. The octane index represents how "slow" the gas burns, not the contrary. The reason high compression engines (like the ones in the NSX) require high octane is to prevent pre-ignition. By putting 87 in your NSX, the gasoline would want to pre-ignite (very bad !) just because of the high temperatures and/or high compression levels, whereas the 91 will resist more to ignition.
Re: Not A Problem
Last time I was buying gas it was 87, 89, 93 octane & in Cal 87, 89, 91.AndyVecsey said:
Yellow Rose
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Pumps
Ok Mr. Shell Distributor, since I used to be a Shell Engineer (actually interviewed for an internal position in Marketing Engineering that builds the gas stations) I guess I will have to get more technical for the average audience than I planned. Yes, each underground tank has its pump.....that feeds the meter aboveground where the hose is. To the average concumer, when we say "pump" they usually think about the pump above ground, not in the tank. So, bullshit back to you. Afterall, the phrase "pay at the pump" hardly means going underground, now does it?
AKUDOU said:Where did you come up with this story? Are you smoking left handed cigs or what?
Ok Mr. Shell Distributor, since I used to be a Shell Engineer (actually interviewed for an internal position in Marketing Engineering that builds the gas stations) I guess I will have to get more technical for the average audience than I planned. Yes, each underground tank has its pump.....that feeds the meter aboveground where the hose is. To the average concumer, when we say "pump" they usually think about the pump above ground, not in the tank. So, bullshit back to you. Afterall, the phrase "pay at the pump" hardly means going underground, now does it?
Re: Pumps
PS Most of the changes Shell made to the retail side came from ideas in the Jobber network, not engineers.
This is the bullshit you wrote Mr Engineer:Motorists A fills with 87. Motorists B arrives at the same pump and begins filling with 93. Although the handle is pulled and you can hear the pump running, there is a few second delay in hearing the gasoline swooshing into the tank. Why? There is a three-way divert valve that sends the first few pints of gasoline back to the underground tank that motorists A just filled from. After the timer times out, pure 93 octane is now flowing into your tank. Your Turn Andy and by the way where did you dream up this three-way divert valve.AndyVecsey said:Ok Mr. Shell Distributor, since I used to be a Shell Engineer (actually interviewed for an internal position in Marketing Engineering that builds the gas stations) I guess I will have to get more technical for the average audience than I planned. Yes, each underground tank has its pump.....that feeds the meter aboveground where the hose is. To the average concumer, when we say "pump" they usually think about the pump above ground, not in the tank. So, bullshit back to you. Afterall, the phrase "pay at the pump" hardly means going underground, now does it?
PS Most of the changes Shell made to the retail side came from ideas in the Jobber network, not engineers.
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Re: Re: Not A Problem
I noticed during a recent trip that Sunoco still has stations with six or more flavors ranging from 87 to 94 (I thought it was higher but I just checked their site and it looks like 94 is now tops). We used to have those around here, but no more.
AKUDOU said:
I noticed during a recent trip that Sunoco still has stations with six or more flavors ranging from 87 to 94 (I thought it was higher but I just checked their site and it looks like 94 is now tops). We used to have those around here, but no more.
Re: Re: Re: Not A Problem
Sunoco is primarily in Ohio, WV, Penn they even have economy 85 octane and racing fuel.................DAYTONA BEACH (August 15, 2003) – The National Association for Stock Car Auto Racing (NASCAR) announced today that Sunoco (NYSE: SUN), the world’s largest manufacturer of premium racing gasoline, will become the "Official Fuel of NASCAR," beginning with the 2004 season.Sunoco Performance Products, with a distributor network selling and promoting three racing gasoline brands – Sunoco Race Fuels, Turbo Blue Racing Gasolines, TRICK Racing Gasoline – offers information on these products on the following web sites: Sunoco Race Fuels at www.racegas.com, Turbo Blue at www.turboblue.com and TRICK at www.trickgas.com.sjs said:
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Yellow Rose
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Back To You
Your Turn Andy and by the way where did you dream up this three-way divert valve.
Ok Mr Jobber, time for a bit of education.....several years ago I was working with the folks at Pasadena Marketing terminal and the Deer Park refinery. Whether or not a particular locale implemented said three-way valves was that region's marketing manager's call. What was good for somebody else may not have applied to you. I was also in touch with the ultra-environmentally sensitive Deerfield Beach marketing folks in Florida. Do you really want to go toe-to-toe with me on this?
PS Most of the changes Shell made to the retail side came from ideas in the Jobber network, not engineers.
Agree - see my above comment about Pasadena and Deerfield Beach. They suggested it, we investigated it.
Your Turn Andy and by the way where did you dream up this three-way divert valve.
Ok Mr Jobber, time for a bit of education.....several years ago I was working with the folks at Pasadena Marketing terminal and the Deer Park refinery. Whether or not a particular locale implemented said three-way valves was that region's marketing manager's call. What was good for somebody else may not have applied to you. I was also in touch with the ultra-environmentally sensitive Deerfield Beach marketing folks in Florida. Do you really want to go toe-to-toe with me on this?
PS Most of the changes Shell made to the retail side came from ideas in the Jobber network, not engineers.
Agree - see my above comment about Pasadena and Deerfield Beach. They suggested it, we investigated it.
Re: Back To You
2 Let's go back and see if we are on the same page before we go toe-to-toe. Are you specifically describing a three product multi-product single hose dispenser or a three product three hose dispenser. I think White92 was referring to a 3 product single hose dispenser. Do you agree? BTW....... I will try and leave out the BULLSHIT!!!!!!!!
Andy First of all thanks for one agreementAndyVecsey said:
2 Let's go back and see if we are on the same page before we go toe-to-toe. Are you specifically describing a three product multi-product single hose dispenser or a three product three hose dispenser. I think White92 was referring to a 3 product single hose dispenser. Do you agree? BTW....... I will try and leave out the BULLSHIT!!!!!!!!
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That's so funny that you put this post up... I do this all the time. i.e. I won't put gas into my NSX from a gas station that has only one nozzle for all octane grades. Not necessarily because of the lower octane from the previous customer, but I always wonder if it's all coming from the same underground tank. I remember as a kid (~1968) a Sinclair station (somewhere in the mid-west) was found to be pumping all octane grades from the same underground tank. Even with 3 nozzles, I wonder
Yellow Rose
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Three Into One
Are you specifically describing a three product multi-product single hose dispenser or a three product three hose dispenser. I think White92 was referring to a 3 product single hose dispenser.
One hose.
Over and out.
Are you specifically describing a three product multi-product single hose dispenser or a three product three hose dispenser. I think White92 was referring to a 3 product single hose dispenser.
One hose.
Over and out.
Re: Three Into One
Do you have anything to back up you prior posts or must we assume that being an engineer everyone should believe everything you say is correct or better yet Gospel after all you are the Saint
Such a short answer Andy (not your style).AndyVecsey said:
Do you have anything to back up you prior posts or must we assume that being an engineer everyone should believe everything you say is correct or better yet Gospel after all you are the Saint
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Yellow Rose
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http://www.gilbarco.com.br/ingles/produtos.htm
Click on the "Advantage Series" then look at the 10th bullet. See how it has a pump within? And you said that I didn't know what I was talking about when I said there is a common pump for all three tanks. Shame shame ye with little faith. The pump that you posted a picture of, is a charge pump to lift the gasoline from underground. The product still has to flow through a positive displacement meter and a bank of cartridge filters, which impose restriction that the underground pumps do not put up enough pressure to overcome.
Gilbarco is the most common brand name of pumping / metering system you will find at gas stations. At one time they were owned by Exxon, but I don't know if that is still the case.
Click on the "Advantage Series" then look at the 10th bullet. See how it has a pump within? And you said that I didn't know what I was talking about when I said there is a common pump for all three tanks. Shame shame ye with little faith.
The pump that you posted a picture of, is a charge pump to lift the gasoline from underground. The product still has to flow through a positive displacement meter and a bank of cartridge filters, which impose restriction that the underground pumps do not put up enough pressure to overcome.Gilbarco is the most common brand name of pumping / metering system you will find at gas stations. At one time they were owned by Exxon, but I don't know if that is still the case.
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