understand fuel gauge!? how much left?

[subodh]

does anyone know how big our fuel tanks are?

but what about our fuel gauge



whats left in the tank when its

7/8 ?

6/8 3/4 ?

5/8 ?

4/8 1/2 ?

3/8 ?

2/8 1/4 ?

1/8 ?

when fuel light is on?



is it possible to tell that way?

 

[Grizzly]

Are you talking about a long bed or short bed? Including your signature would be helpful.



A long bed has a 35 gal tank, however you can squeeze 36 gallons in it. When the needle is pointing at 1/2 tank it should be 18 gal, but the first half of my tank always last longer than the second half. Therefore, the gauge or the sending unit in the tank is not very accurate.



george

 

[rscurtis]

When I did the tank vent mod on my '03, I drove it until the LF light was on, the tank still had almost 5 gallons in it when removed.

 

[jelag]

Here's the key that I've found... I have on most of my trucks 2 tanks that are connected together... . I understand the distance to empty and how far it will go after the light comes on... . I don't care myself personally to drive on the lower 5 gal of fuel... for no other reason that I might forget and run the thing out of fuel... but each truck is a tad bit different...

I know I can drive to the low fuel light and another 12-18 miles... and I've had one of my trucks 15 miles past the 0 on distance to empty... . something I'll never do again...

rscurtis has a great point... LF light is on but theirs 5 gal in the tank but there is no telling how much of that is usable... I'm sure that at least 2 gals won't pump out. . that's my guess of the safety margin for dirt and water that's heavier than fuel to sink and stay at the bottom. .

 

[Prairie Dog]

Remember the fuel is keeping the CP3 cool so a min. amount needs to stay in the tank.

 

[AH64ID]

I have noticed on mine (2" level) that I have burned 10 gallons when it reads 3/4 of a tank. When DTE reads 0 there is about 3. 5 gallons left in the tank. I can't recall right now what else there is.

 

[HBarlow]

The short answer to the original question is nobody knows how much fuel is in the tank at the 1/2, 3/4, etc. full marks. You might be able to determine those figures for your own truck if you can remove it and empty it completely then add fuel one or two gallons at a time.

The tank gauges are not linear. In other words, that is to say that a 35 gallon tank probably does not contain 26. 25 gallons when the gauge shows 3/4 fulll or 17,5 gallons when it is showing 1/2 full. The gauge readings are general guides.

The gauges are apparently designed to move very slowly off the full mark to give some owners the wishful thinking impression that their truck gets amazingly good fuel economy.

 

[AH64ID]

The gauges are apparently designed to move very slowly off the full mark to give some owners the wishful thinking impression that their truck gets amazingly good fuel economy.

That is about as true statement as you can put about fuel tanks.



I was watching a show on cars and it was talking about some car from the early 90's with a digital dash and an 18 gallon fuel tank. The digital dash showed gallons remaining, not fuel level. IIRC it was a DC product, but when you fueled the car it would show 18, but would drop to 17 very quick if the station pump didn't fully fill your car. It ended up in lots and lots of consumer complaints about fuel economy. All they did was remove 17 from the ECM logic, and it would go from 18 to 16 when 16 gallons were measured. It compleatly stopped the complaints about inital economy.



I have a Scan Gauge that tells me what level the fuel sender is telling the ECM. At 50 (1/2 tank) the gauge doesn't read half, its 3-5% off. I don't generally watch the fuel level, and its been a long time but 1/2 is not 1/2, 3/4 is not 3/4 (3/4 on my truck is 71% actual fuel), and 1/4 is not 1/4. The top half is big and the bottom half is small.

 

[Blu-meanie]

I ran mine down to install the vent kit. I was about one mile from home towing when the low level light came on, it had less than 4 gallons in the tank. That information and watching the miles on the tank is all I need to know. After 300 miles towing, I need to start looking within the next 50 miles or so. I would get real nervous knowing how much was left after that light appears.

 

[SWithrow]

I can only pump 20 gallons in after the fuel light comes on. It has been this way since new and the dealer said it was normal for the reserve. Hmm over a 10 gallon reserve, yeah right. Up side is I have never had to worry about the wife running it out of fuel.

 

[subodh]

its a shortbed quadcab year 05. . and i have it in my sig but somehow it dont show when i post!! another thing how to keep this forum from sending email to me all the time?

 

[TCDiesel]

its a shortbed quadcab year 05. . and i have it in my sig but somehow it dont show when i post!! another thing how to keep this forum from sending email to me all the time?

Top of Home Page> Discussion Forum>User Control panel>Under Settings & option> Edit Option. Check or unchecked all contact Option for Your preferences.

 

[MelvinPierce]

As mine hit 0 miles to go, I put in 30 gallons, so 5 left on long bed.

If you want to know how much is in the tank at 1/2, etc. Do it the old fashioned way.

When the tank shows 1/2, go fill it up! What a concept! Remember how much you put in.

MP

 

[JMDancoe]

I never trust a fuel gauge. Even before trip odometers, I figure my fuel mileage, build in a safety factor and fuel when I figure it is needed by miles run. Can honestly say I have never run out of fuel. Came close a time or two.
However, have never been able to convince my kids to get and actual mileage check on their vehicles. They go by gauge and dad has had to rescue them a few times.
Think of your fuel gauge as a politician..... it lies!
______________
86 / 92 D-250 auto 2WD Retrofit 248,000 miles- 94 Ram 1500 4WD auto short bed 307,000 miles - 2000 Jeep Grand Cherokee Laredo 160,000 miles

 

[HBarlow]

You could also say that the fuel gauge is like a politician in that it paints a rosy picture to conceal the truth, you're quickly running out of fuel.

 

[JMDancoe]

True, but I just tend to be more blunt. To me the word politician is synonymous with Liar, Cheat and Thief! but then that's just me...

 

[HBarlow]

Can't disagree with a word you wrote.

 

[CBari]

If I was quit so lazy I would go out to the truck and get the owners manual and quote it directly, but to paraphrase.



This is out of the 2003 owners manual by the way.



When the overhead DTE reads 0 you have a 7% reserve. They go on to say that this is a safety fact to prevent you from running out of fuel.





All of that being said I can tell you from numerous experiences that when the light comes it varies each time how much you have left. I have two tanks and occasionaly will run one completely empty. When I have done this I have had very few vairibles and the overal tank milage has been consistant.



What I am trying to say is that sometimes when the light comes on I can go over 100miles before running out and sometimes it is less than 50.



I to however agree that the gauge is like politians that they lie.

 

[richardcoxid]

I tow a 5th wheel RV so I was interested in what the OP asked, plus I was interested if there was a difference with the RV connected to the truck. Notice that I have a Aero Tanks 60 gal direct replacement tank that sucker must be 6’ long. So my numbers won’t mean anything to those with stock tanks.



I made up 2- 3x5 cards (one for solo and the other for when connected to the RV) with 7/8, 3/4, 5/8 etc. on it, then every time that I full up I enter the number of gallons on my cards. This will tell you approximately how much fuel you have used since the last fill up. In other words I calibrated the fuel gage.



I find that the o’head computer MPG isn’t very accurate, always 2-3 MPG high.

 

[ETavernier]

SWithrow,

My 2004 would only take 27 gallons in the tank in a fillup. The truck came woith a 35 gallon tank. Dodge had venting problems and I could always get in another 10 gallons after the initial "Burp" by filling SLOWLY... indeed it could take 10 minutes for the last 10 gallons.

Rather than just fix the vent I bought a Titan 55 gasllon replacement and fixed the vent at the same time.

Eddie