how do i determine if the gas tank is full

[anon125]

it is a 2006 winnebago 29R.
i believe the tank is 75 gals.
we get 6.88 miles to a gal. towing the honda crv
at pismo beach it was full i believe.
we drove to flag city and intended to refill. 266 miles
the gas gauge has been okay till then.
it took 57 gallons when the guage read 1/4 full. ($233!)
we usually watch the guage and it reads full before the gas pump switches off. the guage stuck at 3/4 then surged up to past full.
when we got to mountain gate past redding (200 miles)... it only took 11 gals!
on monday we hope to cross the 4000 ft siskyou pass and we would rather not run out of gas!
so how do we find out if the tank is full!
thanks all

 

[Utclmjmpr]

If its running all over your foot its full??>>>Dan ;D

 

[PancakeBill]

I let it turn itself off.

 

[myturn]

Once the pump shuts of my rig will take over 10 more gallons. That will keep the gauge on full for at least 2 to 3 more minutes.......See ya at the pumps.

Baron

 

[AndyinLexington]

The filler pipe on ours is very flat between the gas cap and the tank.  The first "auto shut off" event occurs about 15 gallons before the tank is full.  Raising the r/h side of the m/h with the jack on that side helps a lot in getting the tank full.

 

[PancakeBill]

Ahh, mine has a good slant, so the shut off works fine.  If you stop at the F watching on the gauge, you will never be full. 

 

[Gary RV_Wizard]

What you describe is not unusual. Your mpg will vary a lot with conditions (winds, terrain, traffic, speed, etc), and the auto-shutoff on the fuel pump may trip early or late, depending on the angle the coach is sitting, ambient temperature, pump speed, etc. You have to calculate your mpg over several tanks of fuel, to let these anomalies average out.

Just let the pump run till it shuts off. If you suspect it isn't as full as it might be, e.g. the coach is tilted slightly, you can try to squeeze in some more, but is it really important to be chuck full?

 

[bigpemby]

Not trying to hijack this thread, but...  What about fueling up a diesel with the faster filling truck pumps?  Is it okay to run the pump until auto-shut off?

 

[BernieD]

Not trying to hijack this thread, but...  What about fueling up a diesel with the faster filling truck pumps?  Is it okay to run the pump until auto-shut off?

Sometimes you have to worry about splash back. The fuel is being pumped fast enough that when the shut-off kicks in some fuel comes back out of the fill tube and runs down the side of the coach or splashes on you. I generally reduce the fill rate about 5 gallons before I pump as much fuel as I anticipate the tank will take.

 

[Utclmjmpr]

Not only that but the fuel also will FOAM greatly at that speed, then you have to let it settle to get in that last few gallons.>>>Dan

 

[SoEzzy]

If you want the most fuel for your dollar;

Only buy or fill up your car or truck in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening....your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the temperature of the gasoline, diesel and jet fuel, ethanol and other petroleum products plays an important role.

A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps.

When you're filling up do not squeeze the trigger of the nozzle to a fast mode If you look you will see that the trigger has three (3) stages: low, middle, and high. You should be pumping on low mode , thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some of the liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.

One of the most important tips is to fill up when your gas tank is HALF FULL . The reason for this is the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine. Gasoline storage tanks have an internal floating roof. This roof serves as zero clearance between the gas and the atmosphere, so it minimizes the evaporation. Unlike service stations, here where I work, every truck that we load is temperature compensated so that every gallon is actually the exact amount.

Another reminder, if there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up ; most likely the gasoline is being stirred up as the gas is being delivered, and you might pick up some of the dirt that normally settles on the bottom.

 

[anon125]

thanks everyone

 

[AndyinLexington]

If you want the most fuel for your dollar;

Only buy or fill up your car or truck in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening....your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the temperature of the gasoline, diesel and jet fuel, ethanol and other petroleum products plays an important role.

A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps.

When you're filling up do not squeeze the trigger of the nozzle to a fast mode If you look you will see that the trigger has three (3) stages: low, middle, and high. You should be pumping on low mode , thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some of the liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.

One of the most important tips is to fill up when your gas tank is HALF FULL . The reason for this is the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine. Gasoline storage tanks have an internal floating roof. This roof serves as zero clearance between the gas and the atmosphere, so it minimizes the evaporation. Unlike service stations, here where I work, every truck that we load is temperature compensated so that every gallon is actually the exact amount.

Another reminder, if there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up ; most likely the gasoline is being stirred up as the gas is being delivered, and you might pick up some of the dirt that normally settles on the bottom.

Much of this is just not true.  The ground storage tank stays at about 55 degrees F, year around.  The liquid part of gasoline does not evaporate hardly at all.  There are volitile chemicals that do evaporate, but the quantity of liquid is very stable.  The tid-bit about the internal floating roof is also pure fiction.  Fuel coming out of the storage tank is filtered. This email has been going around on the internet for a long time.  Do a quick search on www.truthorfiction.com before believing everything you read.

 

[PancakeBill]

Only buy or fill up your car or truck in the early morning when the ground temperature is still cold

I first heard this in about 1964 in drivers ed from my chem teacher who also happened to teach driver ed.  So.  He was off on that one?  The one thing I wandered about was if you filled early and didn't drive and use up a gallon or so, would the fuel in your tank then expand and overflow in heat of the day.

HHmmmm

 

[John From Detroit]

Let's start with "only fill in the morning" The underground tanks do not change temperature nearly as much as the air above ground, and the pumps are fully temperature compensated so .. this one makes no difference... Now back in the days when the pump had a big glass bottle you filled by hand cranking and then emptied by draining into your vehicle's tank.. Perhaps. but not today.

Re: Fill slowly or swiftly: Now I do admit i fill slowly but that is because if I crank it open as I'd like to the RV won't accept fuel that fast,, I do know why.

The certifiers test the pump at low-flow, medium flow and high flow rates to insure the accuracy at all speeds.  Again, at one time the pump said something like "Accurate at any flow rte from x GPM to Max" but now it's just "Accurate at any flow rate" and they test at low as well as other rates. so once again, that is false.

The one thing that is true is this: It is not a good idea to fill up while the underground tanks are being filled..

This is because the laws allow for some "Contamination" (Water and such) in the bottom of the underground tanks,  The fuel pick up in that tank, just like the one for your generator, is not on the bottom, it's up a bit.. To allow for this.. When the tanker dumps it's cargo into the underground tank this can get "Stirred up" a bit and sucked into the pumps.. Causing you grief.

Two gas companies who's policies I do know both limit the amount of water in the storage tanks to 1/2 of what the state allows by the way.  However one of those has been bought out (It is now BP,)  If the water level gets higher than 1/2 the level the state allows, they send in the sucker truck and suck it out. 

 

[Gordon Groff]

I don't worry so much about water as I used to.  We had an old station that we "stuck" the tanks with water paste every day and never found water.  Modern stations are much better.  Not saying it could not happen, but not as common as it once was.  The other factor is ethanol.  (Think DryGas) The BIG advantage to the gas companies is that ethanol combines with moisture, so they can now sell the water they used to suck out! 

Gordon