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How long before 95 gaz goes bad ?


Pepper9187

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Hi !


Does anyone know how long it would take before the std 95 gasoline turns bad ? (not the benzim)

I think it has like 5 or 10% of ethanol in it, and it's supposed to go bad quicker than standard gas we would use in western countries ?

 

 

Thanks

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I had a car left unattended. Car wouldn't start. Ended up being stuck fuel injectors.

I think other things will go wrong before needing to worry about age of fuel.

Get someone to start and use car once a month if possible.

 

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Gasohol E 10 and E 20 has 10% and 20% ethanol. Anything longer than 6 months may give problems , depending what engine we are talking about.  If it has a carb it could have problems. As suggested , fill up with Benzine and add a fuel system stabiliser and/or fuel system cleaner.

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It is related OMF. The ethanol in the fuel absorbs moisture/water , causing rusting and the blocking of the carb jets and , to a lesser extent , injectors. A full tank has less air space , so less air moisture - water - hence the recommendations to fill up , even with a plastic fuel tank. . Benzine has less of the problem causing ethanol. There are  "Fuel storage" additives and cleansers that help.

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23 hours ago, ktm jeff said:

It is related OMF. The ethanol in the fuel absorbs moisture/water , causing rusting and the blocking of the carb jets and , to a lesser extent , injectors. A full tank has less air space , so less air moisture - water - hence the recommendations to fill up , even with a plastic fuel tank. . Benzine has less of the problem causing ethanol. There are  "Fuel storage" additives and cleansers that help.

Agree, in LoS, with the temperatures and the humidity, strive to keep the tank full.

 

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Gasoline, petrol what ever you call it in your country is a mixture of hydrocarbon molecules. Benzine is only one of the molecules used in the production of gasoline so you technically don't buy Benzine at the pump. Depending on what refinery the fuel came from, where it is targeted to go to and what time of the year the components vary. In a colder climate more butane and propane are added to make easier starting. If left sitting in the tank a long time the light components can evaporate and cause starting problems.

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42 minutes ago, Dazinoz said:

Gasoline, petrol what ever you call it in your country is a mixture of hydrocarbon molecules. Benzine is only one of the molecules used in the production of gasoline so you technically don't buy Benzine at the pump. Depending on what refinery the fuel came from, where it is targeted to go to and what time of the year the components vary. In a colder climate more butane and propane are added to make easier starting. If left sitting in the tank a long time the light components can evaporate and cause starting problems.

Butane and propane are gases at room temperature and pressure. Petrol tanks are not pressurised.The lowest molecular weight straight-chain hydrocarbon that is a liquid at room temperature is pentane.

While ethanol does absorb water from the atmosphere, it forms an azeotrope of 95% ethanol: 5% water, which will be miscible with hydrocarbons as a ternary mixture. It's unlikely water would precipitate out in a tank or injectors. The quickest way to resolve that problem - counter-intuitive as it may sound - is to add more ethanol to the tank, in the form of methylated spirits.

Auto mechanics usually get a balky engine started by spraying ether into the air intake.

I used to leave an old Ford I used as a hunting vehicle for 6 to 12 months on a property in outback NSW. Left the tank almost empty. Disconnected the battery. When it was time to start it up, I'd  take off the air filter to give direct access to the air intake. Reconnected the battery. I'd put a jerrycan ( 20 L ) of gasoline into the tank, followed by 500 mL of methylated spirit. Spray ether into the air intake.

That old Ford started every time.

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Butane and propane are gases at room temperature and pressure. Petrol tanks are not pressurised.The lowest molecular weight straight-chain hydrocarbon that is a liquid at room temperature is pentane.

 

So are you saying there is no butane or propane is gasoline?

 

Actually I am wrong. I don’t think it has propane (C3) but does contain butain(C4).

 

 

 

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20 minutes ago, Dazinoz said:

 

So are you saying there is no butane or propane is gasoline?

 

Actually I am wrong. I don’t think it has propane (C3) but does contain butain(C4).

 

 

 

Sent from my iPhone using Thailand Forum - Thaivisa mobile app

In cigarette lighters, butane is a liquid. That's because it is pressurised. It has a boiling point of 1 degree C, which means at normal temperatures in Thailand ( 30 C ) it would be fully in the gas phase, not a liquid.

There may be trace quantities of butane in gasoline; however, certainly not enough to contribute as a fuel.

On the other hand, LPG is primarily propane and butane.

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In cigarette lighters, butane is a liquid. That's because it is pressurised. It has a boiling point of 1 degree C, which means at normal temperatures in Thailand ( 30 C ) it would be fully in the gas phase, not a liquid.
There may be trace quantities of butane in gasoline; however, certainly not enough to contribute as a fuel.
On the other hand, LPG is primarily propane and butane.


I think working 23 years in an oil refinery in operations actually operation the plant from both outside and in the control room offers me some insight as to how gasoline is made and what components it has.

And to quote:-

Gasoline in the U.S. is usually blended from straight run gasoline, reformate, alkylate, and some butane. The approximate composition is 15% C4–C8 straight-chain alkanes, 25 to 40% C4–C10 branched alkanes, 10% cycloalkanes, less than 25% aromatics (benzene less than 1.0%), and 10% straight-chain and cyclic alkenes.


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1 minute ago, Dazinoz said:

 


I think working 23 years in an oil refinery in operations actually operation the plant from both outside and in the control room offers me some insight as to how gasoline is made and what components it has.

And to quote:-

Gasoline in the U.S. is usually blended from straight run gasoline, reformate, alkylate, and some butane. The approximate composition is 15% C4–C8 straight-chain alkanes, 25 to 40% C4–C10 branched alkanes, 10% cycloalkanes, less than 25% aromatics (benzene less than 1.0%), and 10% straight-chain and cyclic alkenes.


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Your argument is with the laws of chemistry and physics, not with me.

Of that 15% C4 - C8 straight chain alkanes, what percentage is C4?

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13 minutes ago, Dazinoz said:

 


I think working 23 years in an oil refinery in operations actually operation the plant from both outside and in the control room offers me some insight as to how gasoline is made and what components it has.

And to quote:-

Gasoline in the U.S. is usually blended from straight run gasoline, reformate, alkylate, and some butane. The approximate composition is 15% C4–C8 straight-chain alkanes, 25 to 40% C4–C10 branched alkanes, 10% cycloalkanes, less than 25% aromatics (benzene less than 1.0%), and 10% straight-chain and cyclic alkenes.


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yes, ok, and so what?

how long before it goes bad?

 

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1 minute ago, melvinmelvin said:

 

yes, ok, and so what?

how long before it goes bad?

 

As far as I can see, neither you or the OP have defined what is meant by "going bad".

If you mean the fuel is degraded so significantly that the vehicle will no longer run on it, I doubt there is an answer because there are probably too many confounding variables.

 

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1 minute ago, Lacessit said:

As far as I can see, neither you or the OP have defined what is meant by "going bad".

If you mean the fuel is degraded so significantly that the vehicle will no longer run on it, I doubt there is an answer because there are probably too many confounding variables.

 

difficulties with starting,

problems with smooth running, idle or under load

 

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A bit more on the butane discussion. We are both right.

Butane is a gas. However, it is soluble in higher straight chain hydrocarbons.

Butane is 100% dissolved in hexane at 1 C. It's about 75% soluble in hexane at 5 C. As the temperature rises, solubility decreases. It is much less soluble in polar solvents such as ethanol and water.

There are probably parts of the USA ( the colder states ) where butane is quite stable dissolved in gasoline.

Equally, there is probably not much butane in Thai gasoline because of the higher ambient temperature, and higher proportions of ethanol in Thai formulations.

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On 8/27/2018 at 3:49 PM, OneMoreFarang said:

Maybe this is unrelated to your questions. But it seems not unusual that people have problems with rusting tanks if they don't us a vehicle for a long time - independent of the sort of gas.

Ethanol is hygroscopic, causing oxidation (rust) of steel fuel lines, ferrous metal parts, valve seats, injector nozzles. It also attacks synthetic rubber seals. Plus, ethanol has only 45% thermal value of gasoline, ie higher fuel consumption. Add environmental damage growing ethanol producing crops. Insane idea. Makes me bloody mad, very bad science for profit. (Sorry, old engineer who warned about this years ago).  

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16 hours ago, Lacessit said:

A bit more on the butane discussion. We are both right.

Butane is a gas. However, it is soluble in higher straight chain hydrocarbons.

Butane is 100% dissolved in hexane at 1 C. It's about 75% soluble in hexane at 5 C. As the temperature rises, solubility decreases. It is much less soluble in polar solvents such as ethanol and water.

There are probably parts of the USA ( the colder states ) where butane is quite stable dissolved in gasoline.

Equally, there is probably not much butane in Thai gasoline because of the higher ambient temperature, and higher proportions of ethanol in Thai formulations.

Yes. I was very aware of what you were saying about the vapour pressures and boiling points of butane and propane. Like I said I worked in operations actually operating the plant that makes the various fuels. I have an electrical background and chemistry was one of my worst areas in school and college. I relied on the chemical engineers at work to tell me what was needed to be done to produce the various components of gasoline to specific standards. I knew butane was added but did not know percentage as that was not in my area of operation. Last night I contacted one of my friends at the refinery to check up for me on percentages. He was on shift today so replied quickly. Now these figures are what is used at the Caltex Refinery in Queensland, Australia. The winter  blend of unleaded petrol (gasoline) contains 5% butane and is as high as 14% for super unleaded.

 

Obviously different refineries in different countries would use different percentages. As you say in Thailand the percentage would be low due to the higher temperatures. 

 

I also asked him about the timing of fuel going "bad" but there is no definitive times and basically said what others have said on here.

 

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7 hours ago, jgarbo said:

Ethanol is hygroscopic, causing oxidation (rust) of steel fuel lines, ferrous metal parts, valve seats, injector nozzles. It also attacks synthetic rubber seals. Plus, ethanol has only 45% thermal value of gasoline, ie higher fuel consumption. Add environmental damage growing ethanol producing crops. Insane idea. Makes me bloody mad, very bad science for profit. (Sorry, old engineer who warned about this years ago).  

Don't get me started on Manildra in Australia. A complete rort to placate minority Nationals.

Ethanol is a polar solvent. Hydrocarbons are non-polar. That's why rubber seals had to be formulated anew to resist attack by ethanol.

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