Fuel / gas tank capacity

[jloyva]

this is NOT normal... I had the same issue as you, it just wasn't adding up. The issue is that your tank is probably not topping off. There seems to be a small handful of people with this issue on the forum. A few have also had a gas leak and after replacement of the gas tank they were able to top off.

I haven't been able to have the dealer diagnose it yet, will be taking it in soon. I have a 4DR so I should have the 21.5 gallon tank, when I run my tank almost dry I can only fill up to 18.5 gallons and the pump pops. The gauge shows "full" at this point like you but there is still 3 gallons more it can take. Others have suggested pumping on the "slower" speed on the pump and this does not work for me. Happens at every gas station I go to, not just one spot.

The reason I know 100% I can confirm this issue at least on mine is that if I hold the pump manually just squeezing the pump as lightly as possible (way slower than the first click on the pump handle) I can actually get it to fill those last 3 gallons, it just takes FOREVER. So something does appear to be wrong and I would guess you might be having the same issue as me. On my JK I could fill up to 21.5 gallons no problem so I know this isn't right on my JL.

Try running your tank all the way down like to less than 10 miles remaining so you know you have just about nothing left, and see if you can manually fill in some more gas very slowly after the gas pump pops.

Thank you for the informative reply. As of right now it's not a huge issue, but I'm going to start paying more attention at every fill up. I would like to run it down to almost empty but I'm afraid of burning out the fuel pump. I've got a 2002 Exploder which needed a fuel pump at around 88k and then another one at 112k, so I'm kind of gun shy about running the tank too low. Give me an external fuel pump any day. I replaced the one in my CJ-7 on my lunch break at work back in 1992.

Wow, that makes me sound old.

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[RussJeep1]

So I'm getting close to 3,000 miles on my two door Sport S and so far have not paid attention to mileage and such, but I'm driving to work and the range says 60 miles so I stop to get gas. Based on my current average mileage of around 23 mpg that means I should have around 2.5 gallons left, let's round it up to 3. I put in 12 gallons and the tank is full which makes only 15 gallons. According to my build sheet and all the literature I'm supposed to have an 18.5 gallon tank. So what happened to my extra 3.5 gallons?

Jim: in jest...most people get the tank capacity wrong. They fail to factor in the fact that the Wrangler can store Rotopax tanks on its roof, while most other vehicles can't...

 

[jloyva]

Jim: in jest...most people get the tank capacity wrong. They fail to factor in the fact that the Wrangler can store Rotopax tanks on its roof, while most other vehicles can't...

So the capacity is really more of an undefined number decided by the individual owner. This makes complete sense.

 

[Shaved Ice]

I had a similar “issue” with my last Power Wagon. The reality was that when the computer said I had less than 10 miles left, I still had 3+ gallons in the tank. I didn’t mind. I considered it a buffer to keep me from running out. I know this because I ran it 20+ miles past what should have been “0 miles until empty”. I suspect our JLs have the same (probably unintentional) buffer. I haven’t tried it out yet though.

 

[jloyva]

I had a similar “issue” with my last Power Wagon. The reality was that when the computer said I had less than 10 miles left, I still had 3+ gallons in the tank. I didn’t mind. I considered it a buffer to keep me from running out. I know this because I ran it 20+ miles past what should have been “0 miles until empty”. I suspect our JLs have the same (probably unintentional) buffer. I haven’t tried it out yet though.

This is my hope. A buffer is a good thing, but it will take a while to figure out (and possibly a misjudgement or two).

 

[Rhinebeck01]

@jloyva

This past forum thread will give you some insight on this:
https://www.jlwranglerforums.com/forum/threads/fuel-low-light.7297/#post-159578

 

[303rider]

I have this issue too and maybe worse.

I have a brand new JLUR. 21.5 gallon tank. Went down to empty with the light on for about 20 miles.

I went to fill the tank and it would only put 16.5 gallons. The major issue is that when I get in after the fill it shows a full tank.

Going to the dealer next week.

 

[HoosierJL]

I believe the OP may be mistaken about 2 door capacity. I have a 2019 2 door and my owner's manual says I have 17.5 gallons instead of 18. I ran it down until I was no longer seeing miles remaining but a message to fuel it now. I was able to put in 16.7 gallons.

 

[wrc777]

I have this issue too and maybe worse.

I have a brand new JLUR. 21.5 gallon tank. Went down to empty with the light on for about 20 miles.

I went to fill the tank and it would only put 16.5 gallons. The major issue is that when I get in after the fill it shows a full tank.

Going to the dealer next week.

That is about all we have ever put into our 2018 jlur.

 

[allieboy]

Not judging, but are you a little person? They have a terrific gathering in liberal, Kansas every year if so.

Brett

A crowded elevator always smells different to a midget.

 

[jloyva]

I believe the OP may be mistaken about 2 door capacity. I have a 2019 2 door and my owner's manual says I have 17.5 gallons instead of 18. I ran it down until I was no longer seeing miles remaining but a message to fuel it now. I was able to put in 16.7 gallons.

I am correct in my fuel tank capacity, see attached picture from my build sheet.

It also appears they reduced the fuel tank capacity based on the order codes from the order guides:

2018 order guide - 18.5 gallon fuel tank (NF2)
2019 order guide - 17.5 gallon fuel tank (NF3)

Also my 2018 OM lists capacity as 18.5/17.5 gallons, so it appears they knew they were going to do this. I am just completely baffled why.

 

[Strommen95]

I am picking up my JLU tomorrow, so bare in mind my experience is with my JKU and not JLU. The JKU has a 22.5 gallon tank. My gas light would always come on around 60-65 miles left until empty. When I’d fill up, I’d always be between 17-18 gallons, meaning there was still 4.5-5.5 gallons left. When it said “nearly empty” or whatever instead of a mileage range, I’d just keep driving it. I think the most I ever filled up was 20 gallons one time when I really tried pushing it, and still had 2.5 gallons left.

IMO, Jeep purposely puts the gas light on early so nobody would get stranded. This is important for off-roading when one might be fairly far from a gas station.

 

[HoosierJL]

I am correct in my fuel tank capacity, see attached picture from my build sheet.

It also appears they reduced the fuel tank capacity based on the order codes from the order guides:

2018 order guide - 18.5 gallon fuel tank (NF2)
2019 order guide - 17.5 gallon fuel tank (NF3)

Also my 2018 OM lists capacity as 18.5/17.5 gallons, so it appears they knew they were going to do this. I am just completely baffled why.

Well that IS interesting. I had no idea that they changed the reported tank size on the 2019s.

 

[Captain Skip]

I just got the build sheet for my 2020 JL Sport S emailed from Jeep. I have a 17.5 gallon tank listed for my JL. But, there's this a couple pages later, does this mean I have a 21.5 gallon tank or does it mean they put 4 extra gallons of gas into the tank at the factory? By the way, I went out for a day trip today and averaged 26.2mpg with my 3.6 - all back roads and secondary roads. On limited access highways doing 65 to 70 mph I average 20 to 21mpg.

Equipment Listing

• 
  * 4 Additional Gallons of Gas
  
  
  
  
  
  
  
  
  

 

[jloyva]

I just got the build sheet for my 2020 JL Sport S emailed from Jeep. I have a 17.5 gallon tank listed for my JL. But, there's this a couple pages later, does this mean I have a 21.5 gallon tank or does it mean they put 4 extra gallons of gas into the tank at the factory? By the way, I went out for a day trip today and averaged 26.2mpg with my 3.6 - all back roads and secondary roads. On limited access highways doing 65 to 70 mph I average 20 to 21mpg.

Equipment Listing

• 
  * 4 Additional Gallons of Gas

It just means you get 4 gallons from the factory. Per my 2018 OM the 2 door has a 18.5/17.5 gallon tank and the 4 door has a 21.5 gallon tank.

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