How's your 2.0 MPGs lookin?

[Heimkehr]

2019 JLUR - No lifts, stock tire size. I use Sam's Club gas almost exclusively (87 octane).

I'm at around 1,250' above sea level and I live in the foothills of the Appalachian Mountains... I have been getting 10.5 - 20.5mpg for the past year... I put new tires on the Jeep a few weeks ago and it dropped instantly to 17.0mpg... (BF Goodrich K02's, same as original tires)

I have 50,100 miles on my Jeep and drive the same route nearly every weekday, weekends vary somewhat.

There's a 20 lb. difference, per corner, between the factory wheel/tire combo on my JLU, and the winter wheel/tire combo that was purchased new last winter. My fuel mileage dropped by 3 mpg during the first tank with the winter shoes installed.

That 3 mpg difference was a slightly bigger penalty than I had anticipated being attributable to the 80 lb. bump in unsprung weight (which is pretty modest, IMO). Possibly the reduced efficiency of winter-blend gasoline is also a causative factor here. FWIW, now I know what to expect.

Like you, Scott, my driving habits tend to change very little during the year.

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[JSFoster75]

There's a 20 lb. difference, per corner, between the factory wheel/tire combo on my JLU, and the winter wheel/tire combo that was purchased new last winter. My fuel mileage dropped by 3 mpg during the first tank with the winter shoes installed.

That 3 mpg difference was a slightly bigger penalty than I had anticipated being attributable to the 80 lb. bump in unsprung weight (which is pretty modest, IMO). Possibly the reduced efficiency of winter-blend gasoline is also a causative factor here. FWIW, now I know what to expect.

Like you, Scott, my driving habits tend to change very little during the year.

At first I assumed it was the winter blend fuel here, but I can't imagine it magically changed at the same time I put new tires on...? The weight in/on my Jeep rarely changes, although I may start looking at weight reduction...

 

[Pinky Tuscadero]

First 9 months average almost entirely city at about 26.4 mpg, felt great beating the numbers for a change and then...
After the lift and 37's...................
Lets just say, yeah, they were all correct in the big hit I would take
When I get a long term average on the new set up I'll post it but so far... ouch !
And Yet ... I'd def recommend it anyways if just for the "coolness factor" alone

 

[4x4Punk]

22 2-Door Sport. Stock it was pulling 22 MPG out of the gate. After 35" tires, 2" lift, and removing those stupid little air dam things off the bumper, on average I'm in the mid-high 16's. Down as low as 15 if it's all city driving, and up to 18.7 if mostly freeway.

 

[joliett]

On my completely stock 2021 Rubicon Unlimited, I was getting 21 - 22 mpg like clockwork, and never waving. For the first 1-year life of the truck's 20k miles, for every fill up, the computer would register 21 - 22. All of a sudden, after having the steering box updated to the latest box (which fixed the 3" of loose steering wheel play) my gas mileage started to display 18 - 19 mpg. I also had a four-wheel alignment performed.

My eyes almost popped out of my head. No change in tire inflation, no change in gas quality, no change in driver or driving style.

I have always used only Top Tier regular gas.

What could be wrong? The engine idles like a kitten, smooth and steady.

I don't know what to do? Help!
I have the specs of the newest 4-wheel alignment, and everything is in spec.

 

[Carlton]

On my completely stock 2021 Rubicon Unlimited, I was getting 21 - 22 mpg like clockwork, and never waving. For the first 1-year life of the truck's 20k miles, for every fill up, the computer would register 21 - 22. All of a sudden, after having the steering box updated to the latest box (which fixed the 3" of loose steering wheel play) my gas mileage started to display 18 - 19 mpg. I also had a four-wheel alignment performed.

My eyes almost popped out of my head. No change in tire inflation, no change in gas quality, no change in driver or driving style.

I have always used only Top Tier regular gas.

What could be wrong? The engine idles like a kitten, smooth and steady.

I don't know what to do? Help!
I have the specs of the newest 4-wheel alignment, and everything is in spec.

Help?!?!

You're acting like a minor change in mpg is an emergency...

Doubt anything to do with steering box or alignment changed your MPG. Weather is colder now which lowers MPG. Also gas stations have switched over to the winter blend of gas which does the same... If you noticed it in the summer you were probably running your AC...

 

[joliett]

As I previously wrote, my mpg never went below 20 - 21 even 22 mpg. I don't mean instant mpg reading, I mean never. I had the jeep all through last winter and my mpg was never below 20 mpg. Usually 21 or as high as 22. Now it stays in the 18's.

 

[El Zilcho]

On my completely stock 2021 Rubicon Unlimited, I was getting 21 - 22 mpg like clockwork, and never waving. For the first 1-year life of the truck's 20k miles, for every fill up, the computer would register 21 - 22. All of a sudden, after having the steering box updated to the latest box (which fixed the 3" of loose steering wheel play) my gas mileage started to display 18 - 19 mpg. I also had a four-wheel alignment performed.

My eyes almost popped out of my head. No change in tire inflation, no change in gas quality, no change in driver or driving style.

I have always used only Top Tier regular gas.

What could be wrong? The engine idles like a kitten, smooth and steady.

I don't know what to do? Help!
I have the specs of the newest 4-wheel alignment, and everything is in spec.

NOw that you mentioned it, I had similar change in my MPG around the time my steering box upgrade...

 

[JSFoster75]

Help?!?!

You're acting like a minor change in mpg is an emergency...

Doubt anything to do with steering box or alignment changed your MPG. Weather is colder now which lowers MPG. Also gas stations have switched over to the winter blend of gas which does the same... If you noticed it in the summer you were probably running your AC...

@joliett
20% isn't that minor, and yes, fuel blends can affect it. If none of the factors you mentioned are in play, then there may be something else going on. Before I traded my Jeep, I went from a consistent 20.5mpg to a consistent 18.5mpg just by putting new tires on... They were the exact same tire, just new... It was enough to irritate me...

 

[joliett]

Thanks for your reply. You're correct, it's not minor. I mean for over 1 year, I consistently got over 20-21 mpg. That's through the winter. I was trying for over 22 mpg. Then all of a sudden, the mileage dropped to 18.5. I just opened the air intake and there was nothing special in there, no blockage. I'm calling Jeep Cares right now.

 

[Flatties 4ever]

I experience anywhere from 18 mpg to 32 mpg - I've noticed the computerized 2.0T is VERY sensitive to a multitude of variables. Biggest changes in mpg I've experienced are due to idle time, time under boost and speed. While these are obvious variables, I didn't expect such large effects to overall mpg. It's almost as if the computer changes parameters for awhile before returning to normal.

 

[Mikester86]

With 2.5” lift and 35’s looking closer to 18.5 MPG on 87 octane. Factor in its Winter fuel season.

 

[joliett]

As I said before, I owned this truck through 2 winters. The change in gas during winter months did not really affect my mpg before; neither did driving with A/C on, or the top and windows up or down. I'm not nit picking this...seeing my mpg previously show consistently 20-21, 21.5, 21.7 and never below 20, all of a sudden go to 18.5 was very surprising and worrisome.

Also, I have consistently driven with top tier 87 octane for most of the time since I owned this Jeep, and the grade of gas did not materially affect my gas mileage. This Jeep is the 3.0-liter turbo charged 4 cylinder.

I have taken care of my Corvette and Porsches all through the years, since I was 15 - I'm 74 now. I generally repair all my cars, finding it enjoyable and a part of owning these cars. I am very familiar with gas mileage and never nitpicked mpg before.

There is something wrong...and finding it will be the challenge -- a tough challenge, but I will find out why.

Hope I can get some help here from our Forum members. Thanks everyone.

 

[unsavory]

As I said before, I owned this truck through 2 winters. The change in gas during winter months did not really affect my mpg before; neither did driving with A/C on, or the top and windows up or down. I'm not nit picking this...seeing my mpg previously show consistently 20-21, 21.5, 21.7 and never below 20, all of a sudden go to 18.5 was very surprising and worrisome.

Also, I have consistently driven with top tier 87 octane for most of the time since I owned this Jeep, and the grade of gas did not materially affect my gas mileage. This Jeep is the 3.0-liter turbo charged 4 cylinder.

I have taken care of my Corvette and Porsches all through the years, since I was 15 - I'm 74 now. I generally repair all my cars, finding it enjoyable and a part of owning these cars. I am very familiar with gas mileage and never nitpicked mpg before.

There is something wrong...and finding it will be the challenge -- a tough challenge, but I will find out why.

Hope I can get some help here from our Forum members. Thanks everyone.

Check you battery voltage while you're driving. Does it stay pegged at 14.1 - 14.2 volts, rather than it's normal behavior of varying voltage depending on whether you are accelerating or slowing to a stop?

It's possible the higher charging current drags the MPG down due to the alternator having to work harder.

 

[Buster1]

As I said before, I owned this truck through 2 winters. The change in gas during winter months did not really affect my mpg before; neither did driving with A/C on, or the top and windows up or down. I'm not nit picking this...seeing my mpg previously show consistently 20-21, 21.5, 21.7 and never below 20, all of a sudden go to 18.5 was very surprising and worrisome.

Also, I have consistently driven with top tier 87 octane for most of the time since I owned this Jeep, and the grade of gas did not materially affect my gas mileage. This Jeep is the 3.0-liter turbo charged 4 cylinder.

I have taken care of my Corvette and Porsches all through the years, since I was 15 - I'm 74 now. I generally repair all my cars, finding it enjoyable and a part of owning these cars. I am very familiar with gas mileage and never nitpicked mpg before.

There is something wrong...and finding it will be the challenge -- a tough challenge, but I will find out why.

Hope I can get some help here from our Forum members. Thanks everyone.

Are you basing your concerns on the on-dash Jeep display? Or are you manually calculating it (Fuelly app or otherwise)?

I use Fuelly and it differs from the Jeep display by about 1 MPG.

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