MPG and range

[PyrPatriot]

Sorry, it doesn't work that way. That low light and ding can mean from a gallon to 3.
That's because it takes the conditions at that time - the CURRENT MPG and does it's calculations.
I've had vehicles with the low fuel warning give me the light in the AM but when I parked it the night before it would show I had 50+ miles left. My own JT low fuel light came on and I had almost 2 gallons left. It took just 20.

A couple of days ago my JT said 70 miles left - my average was 20.3 at the time - yet it took only 17 gallons. Conditions had changed and my current mpg was lower.
My wife's grand cherokee will tell her she's got 120 miles left on the tank and then the next day she's got 100.
With my Silverado it could change at the drop of a hat. It's not based on your average, it's based on the current MPG and other criteria.
If they based it on your average then you hit some wind or hills............

That is what I am saying.

Actually the low fuel light can come on with more than 2 gallons............ I've had it happen. I was just giving one example. My Chevy could be all over the place with how much was left. It's an estimate so there could be 3 gallons left if you have bad MPG at that point.
Low can show up when you have FORTY (40) - there's no rule. I've had it happen with 40, or even 35 on my other vehicles. The point is there's not a hard fast exact rule - I've never had a vehicle, even this JT, where that light comes on with under 25 miles left - it's always 30 or more. I'd be worried if the light came on and I had only 20 miles left on the tank or even only 30.
That's because your mileage may vary as they say - 40 miles left and you are currently getting 8 mpg?
My wife had her's come on when she had fumes left. I had to look up the capacity of her tank one time as I was shocked at how much I got in it - but then she was running an average of 27 at that time.... and was babying it so likely her "current" was also quite high.
They can be pretty accurate, though, and I try to assume it's not joking when it comes on. When I'm hauling my car hauler on I80 in eastern Iowa I make sure I don't let the light come on because the next gas station of any decent reputation could be more than 2 gallons away! ;-)

The user manual and Jeep’s technical service say otherwise. The alarms are SUPPOSED to come on at 2gal and 15mi, respectively

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[Pat2Alaska]

Why did you drive so slow to and from Colorado?

Cuz I’m a grandpa! It already takes too long, 25 would kill me! 70mph across NE to North Platte, then 80mph to Denver, and 50 to 70mph in the mountains to Salida!

 

[Reasons]

I have 400miles now on my Gladiator and I drive pretty conservative. Averaging 18mpg combined city/hwy. 350mile -360mile range. Only mods so far is +120lbs. To the front with winch/steel bumper.

 

[ShadowsPapa]

The alarms are SUPPOSED to come on at 2gal and 15mi, respectively

Almost every vehicle and every book says "comes on at xxx" and it's going to be only under certain conditions.
2 gallons and you have only 15 miles left? That implies you get 7.5 mpg.
Think about those numbers - do they even make sense? 15 miles - you can't get to a station - but 15 miles at their "in town mpg" would also figure out to over 2 gallons. For me that means I had better drive like a very old woman with extreme care to the next closest gas station as I likely won't make it if I don't.
2 gallons comes out closer to what I typically witness at say 19 mpg average combined driving types yeah, that would give 38 which is a bit lower than I have seen the light come on at but at least is closer. (I've seen it at 40)

You can't go by what they say is supposed to happen - it just doesn't work out that way and no vehicle I've ever had - including the numerous Jeeps we have owned, ever work out that way.
15 miles here would leave you totally stranded. 2 gallons may as well if you are pulling a trailer or facing the hills around here.
Thank god they actually come on with more miles left!

Anyway, yesterday we drove against really nasty high winds and through very hilly southern Iowa on way to my wife's family Thanksgiving get-together as her cousin's winery. The wind was bucking the JT the whole way and the hills were 4-5 grades here and there but we still after a lot of driving around got home with 21.3 average mpg over about 100 miles on this tank full. Not shabby at all.
I suspect I'm going to be facing 19-20 typical tank averages, about 18 at worst unless I make changes.

 

[kostik76]

So I want to start a new thread where those who have upgraded their JT's to larger than factory sized tires can post their MPGs and range. Though those running completely stock or just with nonfactory tires/wheels should also post. It will be a one stop thread for all info regarding this subject. Should also prevent recurrent, "What's you MPG?" questions.
I know Smiles per Gallon etc. I get it. I actually don't care about the financial part that much. My reasoning is I plan to use this for an overland vehicle. I have an ecodiesel WK2 that I love the range on. So I'm really trying to decide (like many are) is the increased power and range of the diesel, but likely worse (though still unkown) reliability of the gen 3 ecodiesel, worth waiting for compared to the decreased range and power of the gas engine (though more history showing good reliability).
I plan on doing a lot of cross country trips on 37"s with gear, so If I'd getting a range of less than 300-350 miles with the gasser, but >400 with the diesel then it's worth it ( assuming both have 22 gal tanks).
This is not to debate on merits of gas vs diesel (cost, reliabilty etc.). This is to give myself and those wanting to run larger tires an idea of what to expect. And potentially the MPG/Range difference is between gas or diesel (once released).
Pictures are highly encouraged.

I'd like it to be fairly standardized.
Jeep year & trim: (Rubicon, Overland, Sport)
Mileage: (XXXXX)
Engine: (3.6 pentastar, 3.0 ecodiesl, Future options)
Fuel type: ( 87 octane, 89 octane, biodiesel, etc)
Lift: (stock, Mopar 2", Metalcloak 3.5, etc)
Tire size and model: (37x12.5R17 Nitto Trail Grapplers)
Diff gearing: (3.73, 4.10, 4.88 etc)
Tuned?: (yes/no which ones)
Other add-ons: (Supercharger, aftermarket turbo, CAI, etc.)
Tire PSI: ()
Speedometer recalibrated? (yes/no)
EVIC or hand calculated?:
Local driving conditions: ( Flat, hilly mountains, sea level, altitude, towing, highway, city)
Average MPG:
Anything else of interest.

Sport S 6 speed with regular rims in NY 17.5 or so. Really get killed on rt 17 which has some hills needing to drop down to 4th sometimes. I hate the fact that i could not get lower ratio on manual and max tow. Come to think of it, i will not be buying another wrangler if it is not available and this one is probably going to go back once the lease is over. My previous Sahara 6 speed with max tow did much better just because of the lower ratio. Here i am getting killed in 4 wheel drive, not enough power...

 

[kostik76]

The highway mileage kills - especially speeds above 65 or 70. In Montana where I'm at the speed limit is 80, and doing that speed my stock LE got in the 15's. Going around town I was able to do between 18 and 19 but as soon as I jump on the highway it drops.

I drive close to 80 and on flat i get closer to 19 mpg. hills and i am at 17. stock sport 6sp

 

[PyrPatriot]

Almost every vehicle and every book says "comes on at xxx" and it's going to be only under certain conditions.
2 gallons and you have only 15 miles left? That implies you get 7.5 mpg.
Think about those numbers - do they even make sense? 15 miles - you can't get to a station - but 15 miles at their "in town mpg" would also figure out to over 2 gallons. For me that means I had better drive like a very old woman with extreme care to the next closest gas station as I likely won't make it if I don't.
2 gallons comes out closer to what I typically witness at say 19 mpg average combined driving types yeah, that would give 38 which is a bit lower than I have seen the light come on at but at least is closer. (I've seen it at 40)

You can't go by what they say is supposed to happen - it just doesn't work out that way and no vehicle I've ever had - including the numerous Jeeps we have owned, ever work out that way.
15 miles here would leave you totally stranded. 2 gallons may as well if you are pulling a trailer or facing the hills around here.
Thank god they actually come on with more miles left!

Anyway, yesterday we drove against really nasty high winds and through very hilly southern Iowa on way to my wife's family Thanksgiving get-together as her cousin's winery. The wind was bucking the JT the whole way and the hills were 4-5 grades here and there but we still after a lot of driving around got home with 21.3 average mpg over about 100 miles on this tank full. Not shabby at all.
I suspect I'm going to be facing 19-20 typical tank averages, about 18 at worst unless I make changes.

My apologies for being unclear. The book states that the low fuel light comes on at 2gal remaining (p.122) and the Range changes to "Low" mi when there is less than 10mi remaining (p.114).

 

[ShadowsPapa]

Mine changed to low miles when there were about 30 left - but then that was when last parked. It's not accurate and can't be is the bottom line because the miles left changes constantly. Apparently it reads the current, instant, mpg and goes by that because when I last saw the miles left on the tank it was a whole lot more than 10 but when I drove it next, it came on low miles.
Bottom line, that's a guideline only and shouldn't be relied on to be accurate at all times - mine sure did not follow what the book says.

 

[PyrPatriot]

When does your low fuel light come on?

 

[kostik76]

When does your low fuel light come on?

do not remember but it was enough to go 30 miles or so to the gas station. i do not trust computer to calculate how many miles i have as MPG varies greatly depending on the road, so just get fueled when it is low

 

[Pion]

I drive close to 80 and on flat i get closer to 19 mpg. hills and i am at 17. stock sport 6sp

I'm about that for my commute, but I fight wind in one direction and hills in the other. Overall average is in the high 17's. If I have the rooftop tent and rack on the average drops about 1.5mpg. With the LE version I'm dragging more weight around and its automatic, which may also be a contributor.

 

[ShadowsPapa]

do not remember but it was enough to go 30 miles or so to the gas station. i do not trust computer to calculate how many miles i have as MPG varies greatly depending on the road, so just get fueled when it is low

Varies - there isn't a set miles. It tends to be in the 30s but then the range on the tank or miles left changes as you drive!
It may say 40 now, then 30, then 45 - so there's no use being stuck on a specific miles left when it will come on. Your miles left keeps changing. I've parked at 40 or 45 left and come out the next day to a light coming on and ding as I start to leave the driveway. So does that mean it came on at 45 miles left? I've had light come on and then stop and start again and it wasn't on.

 

[Gecko-JKU]

Jeep engineers have commented before that the Wrangler pads the low fuel light to come on around 4 gallons because of off roading. I wouldn't be surprised if the Gladiator was the same due to shared ECUs.

 

[Big Red Gladiator]

Picked up my LE June 19 and now have 42,600 miles. I have averaged 19.4 MPG. Once in a big rain with lots of wind she was getting only 17.2
When filling up your tank, try to let it rest (or level out because of baffles in your tank). after pausing for a minute I can usually pump another 1/2 to 3/4 of a gallon more of gas.

 

[Br4hm4]

Jeep year & trim: 2020 Overland
Mileage: 380
Engine: 3.6 pentastar
Fuel type: 87 octane
Lift: stock
Tire size and model: stock
Diff gearing: 3.73
Tuned?: no
Other add-ons: n/a
Tire PSI: 40
Speedometer recalibrated? n/a
Local driving conditions: lots of low grade hills, typically stay under 70 MPH
Average MPG:19.2 MPG

I have noticed there is a sweet spot when I am driving from 65-69 MPH. I seem to get the best MPGs. I think I would actually be doing better but With the recent snow and what not, I have had to use the remote start and let it warm up before putting the kiddo in it...I have also let it sit idle running while doing errands and the kid and wife are waiting on me. I am also hoping as I get through the normal break in period, it goes up a bit closer to 20.

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