Does Jeep purposely design their vehicles to get 19 mpg?

[Callsign_DISCO]

Wish I was getting 19.....

'24 JT Rubicon on 315/70R17 Firestone Destination MT2's (which are admittedly heavy), just did a 200 mile round-trip with camper, got 10 mpg, seeing 16-ish in town and on highway when not towing

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[outdoor.adventures]

Not to brag, but I get 13.5 MPG between my house and town (50-55mph busy suburban road with stop lights every 0.5-1 mile, 75% chance of red light), and 15.5 MPG if freeway driving (75-80mph).

For those that want to achieve this excellence: 3" lift, 37" load range E tires, front bumper wings delete

 

[Afternoon Spray]

Assuming stock tire size?





I'd still stick to 4th and see how that changes things. I actually got slightly better mpgs with cruise in 4th on the highway between 55-70mph than I do using 5th and downshifting manually as needed for hills, then returning to cruise after shifting, OR staying in 5th on the highway at the same speeds.
- 5th does NOT like being below 2500rpm for acceleration, not with 3.73s anyways.



When I report my MPGs, I have a 6 speed, 3.73 gears, 255 MTs, and live in rolling hills where the posted speed is no less than 45 but generally 55mph, with stop signs at almost every intersection or a sharp turn dropping speed to below 15mph, just to accelerate back up to 45-55 up a hill.
-Here I see roughly 15-18mpg, and with more consistent highway (still rolling hills, but 55-65mph zones, and rarely slow below 45) I see 17-21mpg (closer to 18-19.5mpg).

-Stock 2021 Willys w/ manual transmission and 49k miles.

I never see 2500rpm in 5th. I think I'd need to be going 80-85MPH or faster. With the stock 33inch KO2s. I do mostly treat it as a 4 speed and only go 5th if I'm going flat or downhill at highway speeds. But I still wish I got slightly better fuel efficiency. I'd be happy with like 17MPG

 

[Dilly’S Willy]

I never see 2500rpm in 5th. I think I'd need to be going 80-85MPH or faster. With the stock 33inch KO2s. I do mostly treat it as a 4 speed and only go 5th if I'm going flat or downhill at highway speeds. But I still wish I got slightly better fuel efficiency. I'd be happy with like 17MPG

Yeah, try a couple days of using 4th instead and updates us, or me via PM.

When I switch to 255/85R17 (from 255/75R17 stock MT size) I expect to drop 1-2mpg all around. But I plan to re-gear to 4.56 after which should restore my mpg 1-2mpg on average.

Might need to re-gear in the future if you don't plan on staying stock. Added weight means a need for added power to maintain rate of acceleration. So if you don't plan on driving 120+, why waste those extra unused gears and instead stay in the powerband more easily?

 

[Afternoon Spray]

Yeah, try a couple days of using 4th instead and updates us, or me via PM.

When I switch to 255/85R17 (from 255/75R17 stock MT size) I expect to drop 1-2mpg all around. But I plan to re-gear to 4.56 after which should restore my mpg 1-2mpg on average.

Might need to re-gear in the future if you don't plan on staying stock. Added weight means a need for added power to maintain rate of acceleration. So if you don't plan on driving 120+, why waste those extra unused gears and instead stay in the powerband more easily?

I'm actually considering going to 255/85/17 Mickey Thompsons. I had the stock falken mud tires on it when I bought it that were about 62lbs a piece and went to the KO2s which shaved 11 lbs per tire. It increased my average from 13.5-14mpg to the current 15-15.5.

The 255/85/17s are only 2 lbs more per tire than the original 33" mud tires I had. I expect I'll have to live with shit MPG if I go back to heavier tires. I try to blame it on my city having a ton of stop lights and hills and rarely driving on the highway.

 

[DJPodratz]

While we are on the mpg subject, does anyone know how far back the computer goes to figure out your average mpg on the display? I am guessing it only computes for the last 100 miles or so.

I believe it goes back until you reset it.

 

[DJPodratz]

The MPG numbers in this thread all sound a bit lower than my experience

With a manual tranny and stock sport I get 4-5 MPG better.

I suspect big tires and auto tranny hurt MPG quite a bit.

 

[Mr Miami]

I wouldn't blame it on the 8 Speed ZF transmissions. The mileage difference between manual and automatic now is minimal. In some cases an automatic may be a MPG lower, but in many if not most cases today, it's a wash. At least so when driving "normally" on the highway when the computer can "outthink" a person when the ultimate shift time is optimal.​

 

[DJPodratz]

I wouldn't blame it on the 8 Speed ZF transmissions. The mileage difference between manual and automatic now is minimal. In some cases an automatic may be a MPG lower, but in many if not most cases today, it's a wash. At least so when driving "normally" on the highway when the computer can "outthink" a person when the ultimate shift time is optimal.​

Mr Miami,

I'm curious about your claim. Are there any studies or data out there looking at identical vehicles with auto v manual transmissions?

I suspect today's automatics are much better than a few years ago, but I am a bit skeptical they are that close in MPG to a manual. Just all of the moving parts have to suck up energy.

Also, no doubt a computer might outthink a human in a single situation (highway as you suggest), but is that really true across ALL driving situations?

Thanks!

 

[Mr Miami]

Mr Miami,

I'm curious about your claim. Are there any studies or data out there looking at identical vehicles with auto v manual transmissions?

I suspect today's automatics are much better than a few years ago, but I am a bit skeptical they are that close in MPG to a manual. Just all of the moving parts have to suck up energy.

Also, no doubt a computer might outthink a human in a single situation (highway as you suggest), but is that really true across ALL driving situations?

Thanks!

True, maybe I was making too much of a generalization. It's even difficult (at least all the dealers I have just looked up) to even find a manual transmission and look at the window sticker on-line. I would still think that a manual vs. automatic in the same configuration would not vary by more than 1 MPG. I could be wrong.

Maybe some people here who have a manual can share their window sticker or at least mention what the City/Highway/Combined says. Not that that proves anything, but I would still think that it is minimal, if at all.

 

[Mr Miami]

Mr Miami,

I'm curious about your claim. Are there any studies or data out there looking at identical vehicles with auto v manual transmissions?

I suspect today's automatics are much better than a few years ago, but I am a bit skeptical they are that close in MPG to a manual. Just all of the moving parts have to suck up energy.

Also, no doubt a computer might outthink a human in a single situation (highway as you suggest), but is that really true across ALL driving situations?

Thanks!

You really got me thinking on this one. I finally did find a Wrangler Sport S with a manual trans with the 3.6 that showed 19/17/23 on the sticker.

Of course there currently is no manual 3.6 on the Gladiators but the automatic Gladiator Sport S stickers show 19/17/22. Virtually the same and that is not taking into consideration the added weight of the Gladiator.

Not at all scientific since they are not identical vehicles but you can see what I was originally inferring.

 

[DJPodratz]

You really got me thinking on this one. I finally did find a Wrangler Sport S with a manual trans with the 3.6 that showed 19/17/23 on the sticker.

Of course there currently is no manual 3.6 on the Gladiators but the automatic Gladiator Sport S stickers show 19/17/22. Virtually the same and that is not taking into consideration the added weight of the Gladiator.

Not at all scientific since they are not identical vehicles but you can see what I was originally inferring.

 

[DJPodratz]

Are they not making manuals any more, or are they just not available from most dealers?

I had to my order mine from the factory in 2021.
My 2021 Sport (Manual) sticker shows 19/16/23, but I typically get 2-4 mpg more.

 

[Dilly’S Willy]

Are they not making manuals any more, or are they just not available from most dealers?

I had to my order mine from the factory in 2021.

My 2021 Sport (Manual) sticker shows 19/16/23, but I typically get 2-4 mpg more.

They stopped offering the manual transmission for the MY2025. MY2024 was the last year you could order any trim with a manual, if the dealer was willing to put in the order (many dealers only wanted to sell what they had on the lot during The Vid).

Also, the ONLY time the 8-speed auto is BETTER for mpg is in the city or hills as it can keep you at the lowest possible rpm while maintaining speed/rate of acceleration. More gears means lower rpm at the same speed and less throttle input in that gear, meaning less air and this less fuel. Shift points make a world of difference, and the biggest difference is those shift point on a 6-speed with 3.73s vs 8-speed.

Also factor many sold models had the automatic transmission paired with either had the MaxTow package (4.10s) or a Mojave/Rubicon which both came with 4.10s as well. So yeah, those closer shift points allow better control. Same as when you re-gear the 6-speed, closer ratios allow more control, at the expense of top speed rpm. But only a few are driving these over 100mph, or have a need to.

 

[Mr Miami]

Are they not making manuals any more, or are they just not available from most dealers?

I had to my order mine from the factory in 2021.

My 2021 Sport (Manual) sticker shows 19/16/23, but I typically get 2-4 mpg more.

@Dillys is correct. The manuals are currently gone, at least in '25/'26. To the best of my knowledge here in the US, the only Jeeps available with manuals currently are the Wranglers. And per the build site, the manual only comes with the 3.6. If you want the 2.0 turbo, you automatically get the automatic. So no manual 2.0's.

Maybe they'll bring back the 3.6 manual Gladiator again. Who knows.

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