Fuel fill-up question

[MetalsGeek]

The tank is plastic. There is virtually NO AIR in the tank. Did you read this entire thread? No. You did not. Your loss.

OK, I'll bite. Please share why is there virtually NO AIR in the tank? A race car type tank with a bladder would be WAY too expensive for Ford. And yeah, I read the entire thread. No mention of a bladder, and post #46 was just a couple of photos. Good info? Sure. Polyethylene? Yes! Amazing? No.

Sponsored

 

[dochawk]

I've read that does occur in a plug-in hybrid. Since they may go ten times as many all electric miles or more.

A friend in our club bought his wife some foreign plugin.

She found that if she drove just right, she could do her 42 (?) mile commute without the ice coming on.

After a few months, it popped up an angry message demanding that she run the engine, as it needed occasional use to keep everything lubricated.

It's not. Just a myth.

Once upon a time, "premium" had more cleaners and whathaveyou than regular.

But that was decades ago.

I assume that that is the origin of the myth.

 

[The Real Maverick]

OK, I'll bite. Please share why is there virtually NO AIR in the tank? A race car type tank with a bladder would be WAY too expensive for Ford. And yeah, I read the entire thread. No mention of a bladder, and post #46 was just a couple of photos. Good info? Sure. Polyethylene? Yes! Amazing? No.

Air is super low density.
Liquid fuel and water is MASSIVELY more dense.

TO BE QUICK I copied and pasted from Google:

"Air can hold a variable amount of water vapor depending on the temperature, but at a typical room temperature (around 20°C), it can hold approximately 17 grams of water vapor per cubic meter, which translates to roughly 0.017 grams of water vapor per liter of air at 100% humidity."

Rounding just to make a point:

Roughly 4 liters to a gallon
Roughly 16 gallon tank
Roughly 64 liter tank.

If empty, and you let in 100% humidity at 20°C you could theoretically let in 1.08 grams of water. 1 GRAM

But, when the liquid fuel comes in at the gas station, it forces that air out. And you are left with a virtually airless tank.

What is a gram in ounces?
About 0.035 ounces of water.
It's one "drip". One "drop" of water.

This is "worst case scenario".

One drip or one drop diluted into 16 gallons of fuel. With even a tiny amount of alcohol, methanol or ethanol, this worst case is harmlessly absorbed and exits the tailpipe.

Burning fuel CREATES 100 times more water. This is why "steam" come out tailpipes in winter. (It's there in summer but you don't see it.)

Hydrogen from fuel hydrocarbons combines with oxygen during combustion and creates water.
Ounces and ounces of water.

Per EPA rules, fuel tanks need to be sealed as best as possible. This is why cars and light trucks have expensive and complex emissions systems.

The only air comes in when you have that gas cap off. And hey, the Mavericks don't even have a gas cap. To be one step better, they have the "capless" self sealing flap inside.

Trivial air • microscopic water.

This is why the majority of people don't worry about it, and perhaps, you need not worry about it either.

Hope that helps.

 

[Tbone289]

By the way, I wrote a wiki for separating gas from ethanol way back in 2007, primarily to test for ethanol content in various blends. I used to go 50-50 to make the math easy since I was measuring for specific content.

I do the same for testing for ethanol % at times. I failed to consider the proportion of water required to get the ethanol to fall out of solution in my previous comment.

 

[TribeFan]

When I was younger I worked at a service station. One of my daily duties was to take the lids off the underground tanks in the parking lot and. use a special long wooden measuring stick and drop it into the tank and record the amount of fuel remaining in inches, But we prepped the lower 6 to 8 inches of the stick with a smear on some paste that would react to water by turning a different color. The point of this process was to see how many inches of water were at the bottom of a particular tank. Needless to say there was always a few maybe more inches of water in the tank. During those days I also got a tip from one of the tanker drivers during one of the refuelings. He said if you ever see a tanker at the station filling the tanks you may not want to pump gas into your car during that time because according to him the water sitting at the bottom of the tank could get displaced during the filling process due to the turbulence of the incoming fuel and you could maybe suck water into your car when you otherwise wouldn't. Ever since that day I tend to shy away from fueling my tank if the tanker truck is there refueling. Now that was long before today's E-10 and maybe water doesn't set at the bottom of the underground tanks like the old days.

 

[The Real Maverick]

When I was younger I worked at a service station. One of my daily duties was to take the lids off the underground tanks in the parking lot and. use a special long wooden measuring stick and drop it into the tank and record the amount of fuel remaining in inches, But we prepped the lower 6 to 8 inches of the stick with a smear on some paste that would react to water by turning a different color. The point of this process was to see how many inches of water were at the bottom of a particular tank. Needless to say there was always a few maybe more inches of water in the tank. During those days I also got a tip from one of the tanker drivers during one of the refuelings. He said if you ever see a tanker at the station filling the tanks you may not want to pump gas into your car during that time because according to him the water sitting at the bottom of the tank could get displaced during the filling process due to the turbulence of the incoming fuel and you could maybe suck water into your car when you otherwise wouldn't. Ever since that day I tend to shy away from fueling my tank if the tanker truck is there refueling. Now that was long before today's E-10 and maybe water doesn't set at the bottom of the underground tanks like the old days.

I can get behind that.

Because:
Ground water can seep into tanks
Rainwater or city water can literally seep in (and does) from the filling port in the parking lot/driveway.
Plus while rare, maybe the tanker brought some water in too.

I am mainly trying to dispel the myth you need to keep your vehicle tank on the full side because "water from air" is going to ruin your truck. (False)

 

[Ken L]

I've never really worried the quality, water or air in a vehicle gas tank, only the quantity.
Using the "Boy Scout Motto" Be Prepared. In winter in try to refuel around 1/2 tank, warmer weather 1/4. Here we tend to get a lot of blowing snow and white outs leading to multi vehicle incidents. Decades ago my Dad got stuck in one, he and many others were snow bound on the highway (401 near London ON) for 8 hours before being rescued by snowmobile and taken to warming centre, and 48 hrs before cars were removed and highway reopened. If he only had a gallon or two of gas left, he would have been very cold or ... You could also slide into a ditch and have to wait hours for a two truck.
It also give you a chance at a better price for gas. In my area prices prices can vary as much as 15cents a litre .60 a gallon.

Ken

 

[Kenv24]

You fill it at half or these days at a quarter due to the price of fuel!

Umum....you're STILL paying the same amount whether you get it now...or later. Funny how human nature convinces us to believe certain things.....LOL

 

[The Real Maverick]

I've never really worried the quality, water or air in a vehicle gas tank, only the quantity.
Using the "Boy Scout Motto" Be Prepared. In winter in try to refuel around 1/2 tank, warmer weather 1/4. Here we tend to get a lot of blowing snow and white outs leading to multi vehicle incidents. Decades ago my Dad got stuck in one, he and many others were snow bound on the highway (401 near London ON) for 8 hours before being rescued by snowmobile and taken to warming centre, and 48 hrs before cars were removed and highway reopened. If he only had a gallon or two of gas left, he would have been very cold or ... You could also slide into a ditch and have to wait hours for a two truck.
It also give you a chance at a better price for gas. In my area prices prices can vary as much as 15cents a litre .60 a gallon.

Ken

Sounds prudent.
There are countless reasons to keep a supply of fuel in your tank. I don't think water condensation is an issue in the current iteration of vehicles. But cold winters, being prepared is wise.

 

[MetalsGeek]

Danger! Science follows.

Air is super low density.
Liquid fuel and water is MASSIVELY more dense.

TO BE QUICK I copied and pasted from Google:

"Air can hold a variable amount of water vapor depending on the temperature, but at a typical room temperature (around 20°C), it can hold approximately 17 grams of water vapor per cubic meter, which translates to roughly 0.017 grams of water vapor per liter of air at 100% humidity."

Rounding just to make a point:

Roughly 4 liters to a gallon
Roughly 16 gallon tank
Roughly 64 liter tank.

If empty, and you let in 100% humidity at 20°C you could theoretically let in 1.08 grams of water. 1 GRAM

But, when the liquid fuel comes in at the gas station, it forces that air out. And you are left with a virtually airless tank.

What is a gram in ounces?
About 0.035 ounces of water.
It's one "drip". One "drop" of water.

This is "worst case scenario".

One drip or one drop diluted into 16 gallons of fuel. With even a tiny amount of alcohol, methanol or ethanol, this worst case is harmlessly absorbed and exits the tailpipe.

Burning fuel CREATES 100 times more water. This is why "steam" come out tailpipes in winter. (It's there in summer but you don't see it.)

Hydrogen from fuel hydrocarbons combines with oxygen during combustion and creates water.
Ounces and ounces of water.

Per EPA rules, fuel tanks need to be sealed as best as possible. This is why cars and light trucks have expensive and complex emissions systems.

The only air comes in when you have that gas cap off. And hey, the Mavericks don't even have a gas cap. To be one step better, they have the "capless" self sealing flap inside.

Trivial air • microscopic water.

This is why the majority of people don't worry about it, and perhaps, you need not worry about it either.

Hope that helps.

Methinks your condescending narrative got off track on combustion products and the number of drops in a gram of water. Rather than rehash your approach, I will just cut to mine.
The "Reid Vapor Pressure" is a standard used to express the volatility of pump gasoline under nominal worst-case conditions (during the summer @ 100 deg F). The federal RVP limit for pure gasoline is 7.8 psia max (E10 is a bit higher). A simple partial pressure calculation from your high school physics class allows us to determine the percentage of gasoline vapor in the tank under steady state conditions (vapor/liquid equilibrium). So, dividing 7.8 by 14.7 tells us that pure gasoline vapor by law can comprise no more than 53% of the volume on a hot day. If we lower the ambient temperature to 50 deg F, the saturation pressure of gasoline drops to about 4.2 psia, so it now comprises only 28% of the vapor in the tank. What do you think makes up the remaining 72%, and what happens each day when the temperatures cycle up and down? That plastic tank would collapse under much vacuum, so it has to be some other gas moving in and out, and air is all we have available. It comes in thru the same evaporative system canister that traps outgoing fuel vapor. We can use relative humidity to estimate how much water vapor is in the air that breathes in and out of the tank each day, and so on. It's not a lot, but it's not negligible either, and the ethanol in my local E10 gas likes to absorb some of it, each and every day.
We may disagree on the numbers, but I think we can both agree that (1) storage is best with a full tank, and (2) no need to worry about it if the vehicle is driven regularly.

 

[AircraftEngineer]

We have stations that sell no ethanol (aka real gas) in all three grades. Why is the premium grade better ?

I expect it doesn't matter but with aircraft engines that run on MOGAS vs AVGAS we always, always, use premium no ethanol. In engine school we used to pour different grades of gasoline into open cups and sealed cups as an experiment and watched over time what happened . . . I feel better using the best gasoline in the cars . . . and in the two-stroke lawn engines. The lowest grade of gas, with ethanol, separated quickly and formed a sludgy varnish mess on the bottom. Hence the lawn mower that won't start in the spring that wasn't put away with a drained fuel system.

 

[sanpablo]

I expect it doesn't matter but with aircraft engines that run on MOGAS vs AVGAS we always, always, use premium no ethanol. In engine school we used to pour different grades of gasoline into open cups and sealed cups as an experiment and watched over time what happened . . . I feel better using the best gasoline in the cars . . . and in the two-stroke lawn engines. The lowest grade of gas, with ethanol, separated quickly and formed a sludgy varnish mess on the bottom. Hence the lawn mower that won't start in the spring that wasn't put away with a drained fuel system.

A very good boat mechanic buddy of mine told me a few years ago to use ethanol free gas in my lawn mower and snow blower. We have 91 octane ethanol free locally but it is usually $1.50 or more a gallon.
I've always run my lawn mower and snow blower empty when put in storage.

 

[Jim D]

When I lived near a nuclear plant the phone book (remember those) printed emergency numbers and a statement to have a full tank of gas. Locally there are fires, flooding, and earthquakes. I always keep the tank full.

 

[d7602002]

A very good boat mechanic buddy of mine told me a few years ago to use ethanol free gas in my lawn mower and snow blower. We have 91 octane ethanol free locally but it is usually $1.50 or more a gallon.
I've always run my lawn mower and snow blower empty when put in storage.

I always use ethanol free gas in anything with a small engine. I'm sure now an expert will come in and say that's a myth, you don't need to run ethanol free in small engines, but I do.

 

[MakinDoForNow]

A very good boat mechanic buddy of mine told me a few years ago to use ethanol free gas in my lawn mower and snow blower. We have 91 octane ethanol free locally but it is usually $1.50 or more a gallon.
I've always run my lawn mower and snow blower empty when put in storage.

I live near Austin zone 8b. I add 2-2.5 oz of Lucas fuel treatment per 5 gallons with injector cleaner (because it's there and gal at Walmart is about $26). Never have any issues with small engines as it greatly slows gas degradation and auto chokes etc stay operational. I will start them about every 6-8 weeks if I think to. (I think I read about snow blowers but if I see some snow dusting the ground I just wait a day or two and it evaporates). I use the Lucas year around in all my small engines with E10 87 octane.

Sponsored