First long trip review + gas mileage/gas tank rant

[Osteodoc08]

I’ve got about 1250 miles on my JTM with the Falken 33” tires. Average 16-18 mpg so far.
Remember the JTM has a lift from the factory even more so than the Rubicon, large factory tire set, aerodynamics of a brick and the hardware is still breaking in. It wasn’t built for high mpg. I accepted that when I bought it as a weekend vehicle. My main daily is a fusion hybrid. 42+ mpg.

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[ShadowsPapa]

My biggest beef is the FUEL TANK. The claim of 22 is likely when it's new, not yet installed, they tip it up onto one corner and fill it.
Like I've said elsewhere here - mine tells me I have 25-30 more miles on it, the nozzle kicks off every time at about 18.5 and sometimes depending on how I hold my mouth and which way the wind is blowing I might get 20 in it, maybe, if I really really let it trickle in at a rate of 1 gallon every 3 minutes. Figuring it's at about 21 mpg average when I fill and it tells me there's 30 left, that means it's got about 1.5 gallons in it?
I've run it down to 20 miles left and gotten 20.5 in it but it takes several minutes with it on a perfectly level slab.
I'd be a lot happier with a slightly larger tank that actually let you fill it instead of shutting things off with a couple of gallons of space still left in the tank. The fact I can stand there and tweak another 2+ gallons into it and actually got 21 in it once, wow, a miracle, tells me there's something amiss with the fill area.
Why does it stop me at 18.5 if I can still get a couple more gallons in it? I can see something like the GC does - when it stops that nozzle you MAY get another .4 or .5 into it. But the JT - there's plenty of room left when it stops you.
That's a pretty small tank for a pickup truck at least in MY opinion. You won't get the best MPG traversing streams, rocky trails and in 4L so I wonder how some of you guys do it crossing no-man's-land for a couple of hours and then doing your thing in the mud and rocks..... you must carry extra gas.

 

[Bswen]

Ive driven my JL for 30 miles when the gas light/miles left said "LOW". Never put more than 19.5 gallons in either of my JLs.

 

[DaveFrat]

Not exactly apples to apples, but out stock Sport S with the 3.73 gears will give us about 26 mpg on a long freeway drive, such as San Jose to San Diego and back.

Lies.... all lies. Lol. Mine with 3.73’s but running 35’s gets maybe 19 on long trips.

 

[FutureOdin]

When I had my Sport S stock, I'd get roughly 24 - 26 MPG if I kept my speed around 50 - 55 (speed limit on this road is 50, so not exactly a freeway)... this would dip down to low 20s when I'd go 68 (this was on a freeway)

 

[Alan_Hepburn]

When I had my Sport S stock, I'd get roughly 24 - 26 MPG if I kept my speed around 50 - 55 (speed limit on this road is 50, so not exactly a freeway)... this would dip down to low 20s when I'd go 68 (this was on a freeway)

When I'm on a freeway I set the cruise control about 3 mph over the speed limit - so, if the limit is 65 I'm running about 68. I rarely need to adjust that speed out here. So, our trip to San Diego and back included a 55 mph stretch going over Pacheco Pass to get to I5, then a generally flat stretch of I5 down to the Grapevine. The southern end of the Grapevine down to San Diego is also reasonably flat. I5 has a 70 mph limit so the cruise was set at 73. Coming back north, as we were descending the Grapevine into the Central Valley the dash actually reported a high of 27.9 mpg!

The current tank of gas has been probably 75% city driving and the dash right now is showing 19.7 mpg.

 

[Blade1668]

On the size of fuel tanks on JT, listed as 22 gallon then only able to fill up short of probably due to the nature of head space for fuel vapor being a gallon plus of space just as a propane tank has a head space not the same reason but as a safety on gasoline fuel tank. The exhaust system passes by the tank at some point so it needs expansion room for vapor (??) My uneducated guess. when "Air loading" vehicle's or rail loading we had to have under 3/4 of fuel in them (normally close to 1/2) and fuel cans filled the same so a 5 gallon one had only 4 gal or less.
I've never gotten the full capacity fill up on any of my other Jeeps MJ, XJ or LJ let alone my JT. Always short about 2 plus gallons.

 

[LostWoods]

My biggest beef is the FUEL TANK. The claim of 22 is likely when it's new, not yet installed, they tip it up onto one corner and fill it.
Like I've said elsewhere here - mine tells me I have 25-30 more miles on it, the nozzle kicks off every time at about 18.5 and sometimes depending on how I hold my mouth and which way the wind is blowing I might get 20 in it, maybe, if I really really let it trickle in at a rate of 1 gallon every 3 minutes. Figuring it's at about 21 mpg average when I fill and it tells me there's 30 left, that means it's got about 1.5 gallons in it?
I've run it down to 20 miles left and gotten 20.5 in it but it takes several minutes with it on a perfectly level slab.
I'd be a lot happier with a slightly larger tank that actually let you fill it instead of shutting things off with a couple of gallons of space still left in the tank. The fact I can stand there and tweak another 2+ gallons into it and actually got 21 in it once, wow, a miracle, tells me there's something amiss with the fill area.
Why does it stop me at 18.5 if I can still get a couple more gallons in it? I can see something like the GC does - when it stops that nozzle you MAY get another .4 or .5 into it. But the JT - there's plenty of room left when it stops you.
That's a pretty small tank for a pickup truck at least in MY opinion. You won't get the best MPG traversing streams, rocky trails and in 4L so I wonder how some of you guys do it crossing no-man's-land for a couple of hours and then doing your thing in the mud and rocks..... you must carry extra gas.

It's not stopping you at 18.5, it still has 2.5 gallons in it and you are filling it up. With a long tank, you will never get all the fuel out and wouldn't want to since all the sediment is chilling at the bottom of the tank. The only way you'll get a true 22 gallons is if it had a sump.

Plus they pad it because CYA. There's always some idiot who would run out and scream about how the truck has 5 miles left so they leave a little extra in there below zero that will get you at least 20 more miles. All said and done it's typically around 10% between the two.

And to be fair, it's a small tank because it's a small truck. There's only so much room under there and larger tanks mean they have to de-rate the payload numbers so they just match what everyone else in the segment does.

 

[ShadowsPapa]

It's not stopping you at 18.5, it still has 2.5 gallons in it and you are filling it up.

Maybe you did not read that I COULD actually get MORE in it if I took my time?
In every case I could get more in.
Sometimes it's easy, sometimes it takes minutes to do it.
You will also note I mention that I did actually get 21 gallons in it. That makes sense as it was averaging over 23 at the time and that meant I could have gotten more in had I driven farther.
It stopped again at 18.5 or so, and I got 21 in it, so no, there was not 2.5 gallons in it.

You can actually pull most tanks down so far there's hardly a gallon left. One way I drain tanks before pulling them is an electric pump connected to the sending unit nipple. I then remove the tank, pick it up and dump the rest into a jug so I can check it out for dirt or rust.

So sorry, yes mine does kick the pump at 18.5 but I CAN get more in it and no there's not more than 2 gallons left, it's simply kicking the pump off unless I feather it. If there were 2 or more gallons left, I'd never get over 19 or so in it, and I can if I try and that's not even seeing gas at the tank.

No sediment in my tanks. I've yet to pull a tank that has sediment in it other than the one from my brother's 69 Javelin and it sat for a couple of years - outside. Even my 82 SX4 with over 160,000 miles on it had a clean tank when I pulled it. Same for my Javelins. The only tanks I've pulled that had sediment, while working as a mechanic, were those few that got crappy gas. Otherwise, none of mine have ever had sediment as is evidenced by the very long life I get from fuel filters.
My cars are able to pull the tank so low there's only about a gallon or so left in the bottom.

This is how the tank from my car looked in 2013 - I used an electric pump to pull gas out and let it dry for a couple of days before I put a new in-tank pump in for my injected engine. It is unwashed, it was simply drained. 1982 car, over 160,000 miles and it sat in a field for 10 years ->

 

[j.o.y.ride]

The mileage sucks

I don't care

MPG is for weenies

 

[j.o.y.ride]

When I'm on a freeway I set the cruise control about 3 mph over the speed limit - so, if the limit is 65 I'm running about 68. I rarely need to adjust that speed out here. So, our trip to San Diego and back included a 55 mph stretch going over Pacheco Pass to get to I5, then a generally flat stretch of I5 down to the Grapevine. The southern end of the Grapevine down to San Diego is also reasonably flat. I5 has a 70 mph limit so the cruise was set at 73. Coming back north, as we were descending the Grapevine into the Central Valley the dash actually reported a high of 27.9 mpg!

The current tank of gas has been probably 75% city driving and the dash right now is showing 19.7 mpg.

Oh man that is brutal. I would never take the truck that far unless it was an off road excursion.

I recently made it to Vegas from San Mateo area in 6.5 hours of drive time by not taking the Jeep. Thats 85mph avg and yeah that's right on. We were doing 90+ on I5, 100+ through Mojave.

I took the truck on a road trip to southern Oregon. Won't do that again. It was about 150 miles shorter and took an hour longer. It's not a very good long haul short time setup.

Now if the destination were an off road trip of significance I would do it. But I want to get out of the I5 hellhole as fast as possible.

YMMV.

 

[brianinca]

Wow! We're heading to San Diego for the 3rd time since June tomorrow AM. 5-6 hrs depending on traffic. I "fixed" the steering with a band-aid of longer LCA's before our first trip (with a cargo trailer). I think the new steering box will make it an even easier trip. We both find the Jeep very comfortable on long trips and on I5 specifically. 99 is awful with all the big rigs clogging things up, we get to I5 as soon as possible.

Oh man that is brutal. I would never take the truck that far unless it was an off road excursion.

I recently made it to Vegas from San Mateo area in 6.5 hours of drive time by not taking the Jeep. Thats 85mph avg and yeah that's right on. We were doing 90+ on I5, 100+ through Mojave.

I took the truck on a road trip to southern Oregon. Won't do that again. It was about 150 miles shorter and took an hour longer. It's not a very good long haul short time setup.

Now if the destination were an off road trip of significance I would do it. But I want to get out of the I5 hellhole as fast as possible.

YMMV.

 

[ShadowsPapa]

Wow! We're heading to San Diego for the 3rd time since June tomorrow AM. 5-6 hrs depending on traffic. I "fixed" the steering with a band-aid of longer LCA's before our first trip (with a cargo trailer). I think the new steering box will make it an even easier trip. We both find the Jeep very comfortable on long trips and on I5 specifically. 99 is awful with all the big rigs clogging things up, we get to I5 as soon as possible.

These trucks make GREAT daily drivers because they are so comfortable on the highway - or any road for that matter)
Drove straight through Des Moines to Fort Wayne last Feb, and then straight through back again 2 days later. We only stopped for fuel (and pee breaks - I'm getting old and drink a lot of water and diet coke). Sure, I stretched and walked a bit each time, but the drive was easy and fun in that truck. Almost 8 hours if you never stopped, over 8 with fuel breaks. Hardly a long drive in that truck.

 

[dickeldan]

Update...just returned to KC today. Little shorter trip at around 580 miles. Got much better mpg at around 18.5 and only filled up once.

 

[rafaelsmith]

I am averaging around 16.5-17.

Its a heavy brick tent going down the road...I am ok with the MPG.

My biggest complaint is with tank size/range. I would like to make some of my more frequent long trips without so many stops.

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