Is this mpg normal?

[Rusty PW]

I’m curious did you regear? I just put 35s on my Sport S with a Mopar lift. Been debating which gears to go with down the line, still at 3.73 atm

Here's a chart to help you.

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[NC_Overland]

Apparently, these engines take a long time to break in. I finally started to get the epa figures around 10k miles. Before then, it was several mpg less.

 

[ShadowsPapa]

Apparently, these engines take a long time to break in. I finally started to get the epa figures around 10k miles. Before then, it was several mpg less.

PCM learning and wear - loosening.
Mine was doing great at 7K - but I drive it like I do my other cars, not like a truck. Take weather and winter vs. summer fuel into account, too...... If you bought it in early November, just for example, and had 10K miles on it by May - some may be fuel, some may be weather, the rest the PCM learning and adapting, and engine wear.
My AMX didn't really do well on fuel until it had about 9K miles (about the time I totaled it)

 

[Mac]

Here's a chart to help you.

That chart looks pretty old as it references being in 4th gear, pretty sure the JT automatic is lower than 1:1, believe it is .67 in 8th gear.

 

[ShadowsPapa]

That chart looks pretty old as it references being in 4th gear, pretty sure the JT automatic is lower than 1:1, believe it is .67 in 8th gear.

That could be the old chart that made its way into this forum multiple times a couple of years ago.
Automatic 6th is 1:1
Manual 4th is 1:1

 

[Rusty PW]

That chart looks pretty old as it references being in 4th gear, pretty sure the JT automatic is lower than 1:1, believe it is .67 in 8th gear.

It's a good useful chart. Say you have 3.73 gears and are turning 2470 rpm with 33" tires. You put on 37" tires. To find the closest gear ratio you need. Look at the 37" tires, go across and find the closest rpm match. Then look at the top for the gear ratio. 2427 rpms will give you a 4.11 gear ratio.

 

[Mac]

It's a good useful chart. Say you have 3.73 gears and are turning 2470 rpm with 33" tires. You put on 37" tires. To find the closest gear ratio you need. Look at the 37" tires, go across and find the closest rpm match. Then look at the top for the gear ratio. 2427 rpms will give you a 4.11 gear ratio.

Look around they probably have one for the current JL/JT with the eight speed. This chart is probably from the JK drivetrain.

 

[chaosjake]

I have a stock JTR on the factory wheels and Falken ATs, and I finally cracked 11 mpg on my last tank. I had been averaging in the low 10s before that.

Almost all city driving, some snow here, have only had the truck on the highway once so far.

 

[Savage1]

Yes.

Follow up question: has anyone taken a Gladiator to the dealer complaining about poor MPG, and had them fix it?

My sales guy texted me a little while after I bought my ‘22 Mojave and asked how I liked it. I told him my mileage I was getting and he said to bring it in for them to diagnose and see if there was an issue as he got a lot better in his. I haven’t done it yet and not sure if I even will.
I didn’t buy mine as a daily driver or anything and I knew the mileage wasn’t great but I thought it’d be at least close to the sticker.
I have a 37 mile drive to work. Flat, no wind and one stop light once I clear town with speeds of around 62 mph. I reset the mpg on the screen and got like 15. I’m showing like 12 around town. I was going to check it the old fashioned way with topping off and checking miles driven but I haven’t drove it back to work since. And yes I drive like grandpa too lol.

 

[u-joint]

Look around they probably have one for the current JL/JT with the eight speed. This chart is probably from the JK drivetrain.

That's absolutely for a JK.

 

[Hootbro]

Here is a Google Sheets link someone did on the JL side that calculates the JL/JT rpm and speed for a given ratio and tire size. Menu drop down selectable.

JL/JT gearing calculator

 

[centra28]

I have a stock Mojave and I get 12-13 when driving around the city and around 17-19 on Hwy only. Combined I consistently get about 15 mph. This is just using the tool that comes built into the instrument panel.

 

[869 KPH]

I have a stock JTR on the factory wheels and Falken ATs, and I finally cracked 11 mpg on my last tank. I had been averaging in the low 10s before that.

Almost all city driving, some snow here, have only had the truck on the highway once so far.

Same, JTR on ATs. I'm averaging just under 12 at about 1,500 miles. Seems low but hoping it will break in better. It does sometimes seem to 'lug' a bit in lower gears, kinda like it's engine braking instead of coasting. I hope it'll learn what's normal soon enough.

 

[NC_Overland]

PCM learning and wear - loosening.
Mine was doing great at 7K - but I drive it like I do my other cars, not like a truck. Take weather and winter vs. summer fuel into account, too...... If you bought it in early November, just for example, and had 10K miles on it by May - some may be fuel, some may be weather, the rest the PCM learning and adapting, and engine wear.
My AMX didn't really do well on fuel until it had about 9K miles (about the time I totaled it)

Nah. I bought it in February and it didn’t start getting better mpg till a road trip in August. The first long road trip. It was either the road trip, or when I ran the shit out of it in the mtns on a curvy road trying to keep up with a Chevy SS and a Civic Si. I was manually shifting it and I was between 4&6k rpm for 20 min or so. I wouldn’t recommend the latter, but it’s was fun with the top off and the alpine cranked and my fiancée sitting next to me having the time of her life. It’s not a sports car by any means, but it held ite own better than it should have. To the point where the dudes in the two other cars pulled over with me after it and asked what I had under the hood. The grip on the Revo 3s is remarkable for an A/T. Especially, E load 285/70/18s.

Once again, do not try this at home kids…

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