2021 Jeep Gladiator Diesel 3.0 horrible MPG

[caryw5150]

2021 Jeep Gladiator diesel on 37's getting 13-14mpg in city driving. wondering if there are issues anyone knows could be causing. drives fine. no issues as i know it, aside from tiny gas tank, reported fuel mpg is horrible.

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[Glad17]

Your 37” tires?

 

[Deleted member 47279]

2021 Jeep Gladiator diesel on 37's getting 13-14mpg in city driving. wondering if there are issues anyone knows could be causing. drives fine. no issues as i know it, aside from tiny gas tank, reported fuel mpg is horrible.

ya bro thats crap. i have a stage 2 tune (300hp) , 37s, and no understanding of anything than full send and get 18. normally i get 20 but i got a huge spare on my roof lol

 

[caryw5150]

ya bro thats crap. i have a stage 2 tune (300hp) , 37s, and no understanding of anything than full send and get 18. normally i get 20 but i got a huge spare on my roof lol

wheres the tune from if you don't mind me asking.

 

[Deleted member 47279]

MRTUNING

 

[Lynn_F]

I've got a 6.5" lift with 40's on stock 3.73's and I'm getting ~18.5mpg. I don't drive crazy but ~75 mph on hwy daily.

 

[Lynn_F]

There is a recall affecting some diesel engines that reduced DEF fluid consumption and increased MPG. I don't remember the specifics but there is a thread on it. Definitely seems like you have an issue. I'm assuming you've calibrated for tire size.

 

[Deleted member 47279]

I've got a 6.5" lift with 40's on stock 3.73's and I'm getting ~18.5mpg. I don't drive crazy but ~75 mph on hwy daily.

Which lift and axles you got for dem forties

 

[Lynn_F]

Which lift and axles you got for dem forties

Stock axles / Evo Enforcer Overland w/ King 2.5's. I daily drive it with beach cruisin' being my primary offroad activity. I do have a trip planned to the Hot Springs off road park next month.

 

[Deleted member 47279]

Stock axles / Evo Enforcer Overland w/ King 2.5's. I daily drive it with beach cruisin' being my primary offroad activity. I do have a trip planned to the Hot Springs off road park next month.

OMG! I must copy you! so pretty!

 

[Escape.idiocracy]

2021 Jeep Gladiator diesel on 37's getting 13-14mpg in city driving. wondering if there are issues anyone knows could be causing. drives fine. no issues as i know it, aside from tiny gas tank, reported fuel mpg is horrible.

Can you drop some more info?
How many miles?
Do you use fuel additives?
Do you consistently fill up at the same gas station?
Do you drain the water fuel separator?

My vote is on the tsb for def consumption….
But my gut is telling me you picked up a crappy tank of fuel somewhere….
Auto Log Book https://a.co/d/2suXiQQ

Seems crazy- but if you don’t have one of these books- you should get one. Log every fill up and location. Great for logging maintenance.
Every now and then I’ll pick up a bad tank of fuel and get terrible mileage. I then black list that station. At a minimum I’ll drain the water fuel separator, if it doesn’t improve post tank I’ll change the filter.

Diesels are sensitive/finicky.

hope things improve

 

[Unkle Luk]

2021 Jeep Gladiator diesel on 37's getting 13-14mpg in city driving. wondering if there are issues anyone knows could be causing. drives fine. no issues as i know it, aside from tiny gas tank, reported fuel mpg is horrible.

have you had the speedometer recalculated? Still shouldn’t be that bad but hat will hurt it

 

[Bonanza]

No advice to give from me, but that's a dope looking ride.

 

[caryw5150]

i love the jeep just trying to delve into this gas mileage issue. i can try seeing about recalibrating the speedo. was gonna get a tune/chip on it so maybe that also would go together with helping to bring this issue to a close.

 

[Unkle Luk]

i love the jeep just trying to delve into this gas mileage issue. i can try seeing about recalibrating the speedo. was gonna get a tune/chip on it so maybe that also would go together with helping to bring this issue to a close.

If you want to check quickly download a gps based speed app on your phone and hit the interstate to see how far you are off. I use speed box.

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