Fuel Tank Capacity

[dcmdon]

Remember kids, just because you might have 2 gallons left doesn't mean the fuel pump can access those 2 gallons entirely. Variances exist there too.....

Yes. This is why I advocated running the car empty to see how much farther it can go after it shows 0 miles.

Its good to know how much USABLE fuel you have left. Even if you normally refill when it hits a half tank, you should know how far you can go in a pinch.

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[IamPro2A]

One flaw I see almost everyone making is that you are assuming that when the pump shuts off, the tank is full.

On our JK, that's pretty much the case. If you top it off, you're lucky to get a few tenths of a gallon before you're spilling gas.

On the Gladiator, I can easily get a couple more gallons if I take my time, and I still have not reached the overflow point. And before someone says it, I know it's going in the tank and not just filling up the neck and/or the vent because the estimated range is still increasing.

 

[dcmdon]

One flaw I see almost everyone making is that you are assuming that when the pump shuts off, the tank is full.

On our JK, that's pretty much the case. If you top it off, you're lucky to get a few tenths of a gallon before you're spilling gas.

On the Gladiator, I can easily get a couple more gallons if I take my time, and I still have not reached the overflow point. And before someone says it, I know it's going in the tank and not just filling up the neck and/or the vent because the estimated range is still increasing.

This is a really great point.
I've had cars at both extremes of this.

My wife's Miata was pretty much full when it clicked. You were lucky to squeeze .4 gal into it before it started spilling. This makes sense since the filler tube was about 14 inches long and went straight up from the tank.

My wife's old Volvo would take another 2 gallons if you spent the time (like 2 minutes) to run a slow trickle into the tank. It was infuriating on road trips when I was going to run the tank to empty within the next few hours and wanted that extra 2 gallons. Normally, I just let it click 2 or 3 times and called it a day.

 

[Gvsukids]

I have ran it down untill light is on and miles left read blank. I stopped before I was completely dry and emptied two Rotopax into the tank. I know it's not healthy but it happens. What's funny is the next day Mopar sent me a email saying that I'm below a 1/8 tank of fuel. Same has happened letting air out of the tires. Mother Mopar is watching over me evidently.

And what was your range after the two cans?

 

[Gvsukids]

https://www.jeepgladiatorforum.com/forum/threads/fuel-tank-capacity.14954/

 

[TroutFishingInAmerica]

And what was your range after the two cans?

You know that would have been valuable information if I would have paid attention. I just dumped them in and filled up when I found a gas station. It would have been a good experiment. Honestly, I usually put ethanol free gas in my Rotopax and it's fairly expensive in my area. I get the ethanol free because I like to use it in other gas powered crap I have but don't use regularly. So with the expensive gas I pushed it a little farther than I probably should before dumping the Rotopax in, but hey, I was happy to have my little backup gas. I really wanted a larger tank or a aux tank but didn't find anything I liked, so Rotopax it was.

 

[Deadeye]

Quality of gas has way more variance than it should, btw. We are getting in to the time of year when winter fuel starts getting stocked. This will have a negative impact. Also, if you happen to stop at a budget joint consistently (like a shoddy Pilot), you might notice the mileage drop off.

My dealer and I were stumped on why my mileage started dipping about 6 weeks after i bought the truck, to the tune of ~5mpg. Did a lot of diagnostics, and then one day I realized I had stopped at the same gas station every stop for a couple months in a row. I went out of my way to go to a expensive marathon for the next few fillups and it was night and day.

 

[Sammar]

I bought my 2021 Jeep Gladiator in March of this year and it supposedly has a 22 gallon fuel tank. The low fuel liight is supposed to come on and chime at 2 gallons left. I also have a gauge that shows my range. Today It said I had 17 miles of range but was bouncing about due to my current MPG going up and down as I drove.

I have been getting between 20-21 mpg and only had 375 miles so this seemed quite odd - at 20mpg my range should be 440miles. I stopped for gas and it only took 17.5 gallons. So WTF size tank do 2021 gas Gladiators have? Is the range calculation majorly messed up? I usually run my tank down - like to 2 gallons or less and do not want to run out No the light and chime did not go off.

Thanks

My 2021 Willys does the exact same thing. Tells me I have a range of 15 miles and then the tank only take about 18 gallons to fill up. I too have wondered if my tank is really 22 gallons but I haven't had the balls or desire to really test it.....

 

[Sammar]

Remember kids, just because you might have 2 gallons left doesn't mean the fuel pump can access those 2 gallons entirely. Variances exist there too.....

I feel like this thread is becoming the epitome of "I want to pretend I'm spending less on gas by filling up less frequently".

Are you saying they made the fuel tank with the line in a position that would not be able to access all the fuel in the tank? Sounds like a total waste of material making a 22 gallon tank that only has access to 20 gallons.

 

[sharpsicle]

Are you saying they made the fuel tank with the line in a position that would not be able to access all the fuel in the tank? Sounds like a total waste of material making a 22 gallon tank that only has access to 20 gallons.

There are many variables that go into this that it's likely different for each situation. But in principle yes, you'll never be able to run a tank completely dry, there will always be gas left over the pump couldn't get. That's just natural.

Also, I didn't say you couldn't access any of the 2 gallons remaining. I said there's no guarantee you could access all 2 gallons.

 

[texanjeeper]

If you want precision, you need to calculate your mileage precisely, or better yet, get an app like Fuelly and plug in the numbers at your fill-up. If you're using the Jeep MPG information in your vehicle, well, let's just say I wouldn't lend too much credence to that information.

 

[Wheelin98TJ]

Are you saying they made the fuel tank with the line in a position that would not be able to access all the fuel in the tank? Sounds like a total waste of material making a 22 gallon tank that only has access to 20 gallons.

Not in the case with the Gladiator, but Jeep has done it before.

Early model TJs had a 15 gallon or 19 gallon tank and they were the same dimensions. They just used a longer fill tube and vent tube on the 15 gallon tank.

 

[No Quarter]

I miss the days when you did not need a GPS to drive around your own home town and you did not need some electronic gizmo to tell you what common sense would easily reveal.

Needle gets close to empty, go get some gas.

 

[Melnik]

I did a thing.
Hey guys, I was wondering this same question ever since I purchased my gladiator and have been filling up potentially an empty tank only to about 18 gallons. The idea of driving empty until engine shut down has crossed my mind but I did not follow through. Unfortunately, today it happened by accident and I have numbers to report. The full tank is indeed 22gal of capacity, of which (depending on your road surface and incline) about 0.5-1 gal at the bottom are not accessible to the fuel pump.

Bottom line my vehicle ran out, shut down completely. I had a little about 0.5-1 gal in a fuel can with me,with that dumped in, the engine would catch on but shut off right away. After filling up additional 2.5 gal from a can and 18.5 at the fuel pump the vehicle was three clicks of full tank.
Conclusion:
Tank is 22gal
Max to getting stranded is 20 gal or 21 gal to vehicle shutoff on an up or downhill.
Everyone’s computer calculators will be different but for me it seems that once the empty light comes on you have about 60 miles/3gal to a point where the fuel pump no longer picking up anything.

 

[ajlacombe]

After a few more fills, what I decided to do is use the avg mpg for each tank and then look at the gallons the fill took. Then I have their estimate and the actual. They are sand bagging by approximately 2 gallons. The next test needs to be heading towards empty (with a gas can in the bed) and see what I get when I get closer. I just hate only using 16 of 22 gallons

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