Gas tank completely empty when at the E line?

so i was driving to arizona a few weeks ago and my needle was even with the end of the gas gauge.

i was pulling jetskiis and made it 45 more miles before i ran out of gas. i was pretty stoked. haha

 

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I had a "fuel problem" in a aircraft once, scared me sh!tless as a kid ... any gas gauge never gets below 1/4 now ... never.

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Been watching my gas needle real close, and have been doing my normal weekly driving (city/ hwy. combined). This tank I got 16.5 mpg...

Here are what the numbers are (needle right over the fuel level marks, not above, not below) Tank filled fully and trip odometer reset:

*Needle at 3/4 mark at 80 miles (1/4 tank of gas, per the gauge) but I used 4.8 gallons (not 5.25), leaving 1/2 gallon 'in reserve' (the difference between the gauge indicated amount and the true gallon amount).

*Needle at 1/2 mark at 155 miles, but I used 9.4 gallons (not 10.5), leaving 1 gallon 'in reserve'.

*Needle at 1/4 mark at 220 miles, but I filled up with 13.3 gallons (not 15.75), leaving 2 1/2 gallons 'in reserve'... I got to a gas station at 222.6 miles to fill up as close to 1/4 tank on the gauge as possible.

If I where to continue driving at 16.5 MPG I would run out at 346.5 miles (16.5 mpg x 21 gallon tank).

The difference between the needle at 1/4 mark and empty is 126.5 miles.

So, as the gauge drops...

Full to 3/4 = 80 miles (4.8 gallons)
3/4 to 1/2 = 75 miles (4.6 gallons)
1/2 to 1/4 = 65 miles (3.9 gallons)
1/4 to 'E' = 85.5 miles (5.2 gallons)
From others and my past experiences, we have 2.5 gallons left when the needle is firmly over the 'E'...
So, 'E' to empty = 41 miles (2.5 gallons)

While your mileage may differ, the gallon level in the tank should be about the same when the needle reaches the different levels...

Full mark is 21 gallons in the tank
3/4 mark is 16.2 gallons in the tank (4.8 to fill)
1/2 mark is 11.6 gallons in the tank (9.4 to fill)
1/4 mark is 7.7 gallons in the tank (13.3 to fill)
Empty mark is 2.5 gallons in the tank (18.5 to fill)

Multiple the gallons above by your truck's MPG to get the miles for each level of your tank.

Let's see if we all have fuel gauges that read the same way!

 

Great post David.

 

Thanks... so top your tank, zero your trip odo., and note the mileage when the gas gauge is dead over the different points... top a 1/4 tank (or E if you dare) and calculate the mileage.

 

I ran mine down so low last nite that the light was still on when I put $6 in it.
On fumes mine takes 17 gals and thats even up in the neck.

Got 358 miles.

 

If you calculate each one of my 1/4 tank mileages and divide it by the avg MPG for that tank, you will get the approximate gallon amount in the tank.

Now i went and did that for all of them and these are the average amounts you have in each 1/4 of the tank...trust me on this. the numbers are in front of you...

5.475
4.021
4.499
2.883

now most of my bottom 1/4 tank mileages were near the lowest they could be so that number would be more accurately represented as 3 Gals.

when you take the averages that are in yellow you get slightly different numbers but that is because the average tank miles factor in the 1st two tanks in which i did not record the avg MPG. however, the difference is slight and here are those numbers as well...

5.375
3.954
4.389
3.036


Sooooooo in the end you actually have about



5.5 in the E to 3/4

4 Gallons in the 3/4 to 1/2

4.5 Gallons in the 1/2 to 1/4

3 Gallons in the 1/4 to Empty


Then 4 more gallons after the light to give you a grand total of 21

 

So gj, that means your gauge is way different from mine.

E to empty: your figures have 4 gallons and mine has 2.5 (off by 1.5)
1/4 to E you have 3, and I have 5.2 gallons (off by 2.2)
1/2 to 1/4 you have 4.5 and I have 3.9 (off by 0.6)
3/4 to 1/2 you have 4 and I have 4.6 (off by 0.6)
F to 3/4 you have 5.5 and I have 4.8 (off by 0.7)

Have you really pulled up to a pump when your needle is firmly on the E line and put only 17 gallons in? I am always putting 18.5 in at that point.

Anyway, I guess each of us needs to do this test to see how our gauge matches the actual amount of gas in the tank.

 

well my E light comes on a little bit before the needle gets to the E mark.

I only go to the E light. I still have about a Gallon and a half before i get to the E mark.

our numbers there for after E light are the same.

 

it seems like our numbers are really only off by about .5 gallons on all the tanks... if you add our numbers from full to 1/4 we are only off by a total .6 or so not bad if you ask me.

you are talking about less than 10 miles per 1/4 tank which is an acceptable margin of error when you consider we are paying attention to our needle on a hashmark... and when is it that we decide it rests firmly on the mark? from how we set in our seat it could look a little different from another guy...i make sure to try and look a the gauge with my head in the same position every time because that can change how it looks. the top 1/4 can be off due to the way you top yours off. i go to the 1st click, wait 10 seconds and then go to the next click.

Edit: You also have to be careful o when you take your reading. if youve just gone up or down a hill it takes a few miles to let the float level back out to the appropriate reading. many factors come in to consideration here but i think we have it down to the .5 gallon with our figures...

 

One more thing to think about...how much data have you collected?

because if you are not getting consistent mileage in all of the 1/4tanks then you can be off a bit. i have data for over 10 tanks. you really need a lot of data or you could be off a bit.

its hard to take an average mpg for the whole tank and divide a certain 1/4 tank by it to get the gallons if that specific 1/4 of a tank was actually a really poor mpg. this is why i've been collecting data...and a lot of it.

I will continue but im going to start topping it off till it is completely full and find out what is the most i can stuff in to the top 1/4 of the tank.

I will go till the e light comes on, fill up and then see how far it goes above my other fill ups when i only went to the second click. i will also collect data on how many miles i get in that tank and then be done with it.

I have one right now but i only have partial data but I hope to eventually have a little laminated card in my visor that hs my high/low and avg 1/4 tank calculations so i'll never have to wonder...i will KNOW how much time i gt left should a bad situation arise one day

 

Well, we could just top the tank at each level and note the gallons put in... but this is not that important... as long as we know there is gas beyond E... at least 2.5 gallons from repeated times I have filled up at E.

Since I did fill up at 1/4 tank, no light... However, my light comes on when there is about 4 gallons in the tank (at E there is 2.5 gallons and at 1/4 there is 7.7 gallons in the tank).

The mileage doesn't matter, we all get different miles per gallon... the gauge accuracy is based on the gallons in the tank. We are using our mileage to estimate the amount of gas at each level of gauge reading, except when we fill up.

I do look close at the needle and confirm its position... and sure there are a few miles where the needle stays over a mark before you notice it move. This is all an approximation.

Thanks for your input... always fun to play with our trucks!

 

I never run mine below a 1/4 of a tank

 

So, how many gallons go in when you are at 1/4 tank???

 

Lowest I've ever had it....wasnt sure if id make it the the gas station. When i turn off the key the needle still goes a bit closer to the E though...so im not sure how much more i had.

 

Again... HOW MANY GALLONS to fill it up? That will tell you how much you had left... and how in the world do you average only 10.3 mpg??? A V-8 in four wheel drive can do better!

 

You have around 3 gallons after the light comes on.

 

We know... it is 3-4 gallons. What we would like to see is documentation... that is what this thread is about... documenting the relation between the gas gauge and the actual gallons in the tank. '2006 Toy Taco' just told us (above) the gauge was at the lowest ever... but failed to add the important data of HOW MANY GALLONS the tank took to fill. That would tell us how much was left in the tank when the needle was THAT low...

Have a nice day!

 

Sorry guys. Wasn't asking a question, just posting a picture. I know how many gallons the tank is and that i have about 3.5 left when the light comes on. I didn't fill up my tank after I took the picture so I don't know how many gallons It was. I let it run low like that again and update with gallons.