Fuel Tank Capacity

[ajlacombe]

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

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[Gvsukids]

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

Is this the first time you've gotten gas? Have you noticed this issue on any other fill ups?

 

[22EcoDs]

Possible bad fuel sending unit?

 

[Jefe1018]

The computer and range light will always go for the conservative side of things in my experience, most vehicles I’ve owned have 3-5 gallons left when the lights come on.

 

[Mr._Bill]

There have been several threads on this topic. The programming is very conservative and reports empty before it is. One theory is that it is done on purpose to minimize the replacement of failed pumps from running the tank dry.

 

[ajlacombe]

I have gotten fuel a bunch but do not want to run the tank dry and my only conclusion was the system is super conservative - to the point that it is not worth a lot. If I have over 4 gallons left when I think I am empty then I can not make use to the tank size and it is rendered into a useful 18 gallon tank.

That programming will achieve its goal of not letting you run it dry but is a waste IMO because I want to know when it will really run out, When researching it - it said it should push 500 mile range on the highway. Maybe I need to put a gas can in the truck and see how far she can go, but hate doing that.

 

[19Delta]

I have gotten fuel a bunch but do not want to run the tank dry and my only conclusion was the system is super conservative - to the point that it is not worth a lot. If I have over 4 gallons left when I think I am empty then I can not make use to the tank size and it is rendered into a useful 18 gallon tank.

That programming will achieve its goal of not letting you run it dry but is a waste IMO because I want to know when it will really run out, When researching it - it said it should push 500 mile range on the highway. Maybe I need to put a gas can in the truck and see how far she can go, but hate doing that.

Do it! (And then report back to us!)

 

[Mr._Bill]

I try to keep my tank full, so I don't have to rush around looking for gas when called in to work. I usually fill up when down to half a tank, and avoid going down to a quarter. I know that I can get about 400 miles on a full tank, but don't try to go that far unless I'm traveling. I use the Flying J app to plan my gas stops, and try not to go below a quarter tank.

 

[Dennis K]

16 and their first vehicle...
Sheesh....

 

[MyRight]

Other than having the knowledge of when it actually runs dry, I don't see the usefulness, as it tells you when you are getting low. Logic tells you that it is time to add some fuel.

 

[AjMac]

Isn't the tank only 18 gallons? So if you are getting 20 mpgs, thats a range of 360 miles. Also, your gas light comes on at 1 or 1.5 gallons left in your tank.

Edit: 22 gallons is what I see, I was wrong. I have the 3.0 and it's 18 something.

 

[sharpsicle]

Range remaining is always an estimate, it is not a factual value. There are so many variables that go into it that it should never be used for critical decisions. It's a reference only. Because of that, it's always going to show you having less range than you probably have as a safety margin for error. If you can't live with that or understand it, I suggest not looking at it.

EDIT: Another important note is that it is not healthy to "run your tank down". I'd stop doing that if at all possible. If you try to fill up closer to the 1/4 tank mark, the estimated range question becomes less important and your fuel pump will be happier. Win-win.

 

[ajlacombe]

The deal for me is filling up less often but on a trip - if I filled up at ¼ tank, I bet I would have 6+ gallons - that is over 100 miles. If the trip is of any length you are filling up more often and you might be sweating reaching a gas station when you do not have to. It is not a major big deal but why can't I know exactly how far I can go? It seems kind of odd that it is that far off - my yesterday 18mile range was actually near 70 miles - that is a bit too conservative for me

 

[sharpsicle]

Because everything in the chain that calculates your estimated range has a margin for error. The tank itself, the fuel pump, the computer, it all has variances and margins. As an engineer I'm sure you can appreciate that as your potential variances or error margins increase, your percent advertised maximum is going to decrease. That's all this is.

If the tank is made to hold 22 gallons +/- 1 gallon, that's an accepted variance of 4.5%. The fuel pump itself is probably accurate to within 3-5% given the difficulties of measuring fluids in motion. That's already a possible variance of 9.5%. Add a safety buffer and you could easily be off by 10 or 11% on the estimated miles remaining. I'm not saying those numbers are actual, but it shows the situation. And I'm probably missing a few variables in here.

I was about to dive into the statistical application of all this, but realized it's not truly useful. All you need to understand is what I stated above. Also realize that your claim of "useful tank size being reduced" is flawed as well. A bigger tank with the same reserve will still net the same benefits. If you had a true-to-size 18 gallon tank, rather than 22, you'd be filling up more often to maintain that 4 gallon reserve. The difference to 22 gallons is still an observed 4 gallons additional as the statistical floor remains the same.

 

[ajlacombe]

Yeah - I just want one number how many gallons of gas - should be fairly precise I do not need the calculations. I just want to know how much gas is left. Yes every car is different so I would see when the light comes on and now that I know the tank is definitely 22 gallons, I will know how many gallons are left (approximately) at the light. I drive infrequently these days so I have to be more rigorous to figure this out. I appreciate all of the help!

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