Backwards MPG?

[Jeep_friend]

Hi all,

I recently brought a 2021 Gladiator to add to my Jeep fleet (2015 Willys Wrangler).

I generally drive the Gladiator on back roads to and from work and get about 17 MPG.

I have taken it on the freeway more recently, I expected to see about 22 MPG however I am seeing 12-14 MPG at highways speed.

I noticed I am running about 2.5-3k RPM while at highway speed, I was playing with the sport shift to see if going into a higher gear would change RPM and MPG but it really didn't do much.

Anyone else experience this (I assume this is not "normal")? Could the truck have been re-geared? If it may have been re-geared, to what ratio does my description lead you to believe it was changed to?

Thanks in advance.

Sponsored

 

[OHJeeper]

I get slightly better "city" MPG if I drive anywhere over about 72 MPH on the highway. As speed increases from there (for me) my MPGs suffer mightily. It's the fantastic aerodynamics of the JT (and I have a stubby bumper)

 

[ZoMojave]

If your JT looks like mine, I have the same issue.

 

[briscoelab]

Do you have different sized tires than stock, and if so did you recalibrate the speedo?

 

[ShadowsPapa]

Hi all,

I recently brought a 2021 Gladiator to add to my Jeep fleet (2015 Willys Wrangler).

I generally drive the Gladiator on back roads to and from work and get about 17 MPG.

I have taken it on the freeway more recently, I expected to see about 22 MPG however I am seeing 12-14 MPG at highways speed.

I noticed I am running about 2.5-3k RPM while at highway speed, I was playing with the sport shift to see if going into a higher gear would change RPM and MPG but it really didn't do much.

Anyone else experience this (I assume this is not "normal")? Could the truck have been re-geared? If it may have been re-geared, to what ratio does my description lead you to believe it was changed to?

Thanks in advance.

LOL - normal for almost any vehicle, worse for bricks.
What do you define as highway speeds? I take it from your RPM you ,mean 75-80+

Wind resistance, drag, increases exponentially over about 60 mph which means it's a steep slope down as you go over that speed. I get my best mpg 45-55, 60 it sort of tops out. And that is a DUH as it fits science perfectly.
Add to the fact that there's a fair picture of these in another post above - a cow is more aerodynamic.
Anything I've ever owned has done far better 45-55, and gone down the proverbial litter box at 65 and higher.
It's going to get its very best in stock form with stock tires. Make changes - expect it to go down.

Welcome to automotive science, is all I can say. You are describing cars and trucks everywhere.

It's the fantastic aerodynamics of the JT (and I have a stubby bumper)

The best bumper for mpg covers the fronts of the front tires. That means the stock plastic bumper. Expose the fronts of the tires and you see mpg loss.
(likely you already know this from the 2 dozen or so other "my Gladiator MPG sucks! Bad truck!" threads. )

Could the truck have been re-geared? If it may have been re-geared, to what ratio does my description lead you to believe it was changed to?

No way to answer as you haven't said what level of Gladiator you have (sport, max tow, Overland, Mojave, Rubicon, High Altitude, etc.) and what you define as highway speed. That could be anything from 65 to 85 so until you give us an exact speed in MPH and what gear it's in at that speed, and what tires are on it, all we can do is throw darts at numbers.

 

[DBravo]

Hi all,

I recently brought a 2021 Gladiator to add to my Jeep fleet (2015 Willys Wrangler).

I generally drive the Gladiator on back roads to and from work and get about 17 MPG.

I have taken it on the freeway more recently, I expected to see about 22 MPG however I am seeing 12-14 MPG at highways speed.

I noticed I am running about 2.5-3k RPM while at highway speed, I was playing with the sport shift to see if going into a higher gear would change RPM and MPG but it really didn't do much.

Anyone else experience this (I assume this is not "normal")? Could the truck have been re-geared? If it may have been re-geared, to what ratio does my description lead you to believe it was changed to?

Thanks in advance.

'20 Gladiator Overland 49k miles, stock suspension and wheels/tires (255/70/R18 Goodyear Wrangler ATA), Hard Tri-Fold Tonneau cover. Just returned from a 1200 mile trip and averaged 22.5 highway. I average 17-19 city and it takes a couple hundred miles of solid highway driving before I see it adjust up.

 

[AverageOverlander]

Ditto what ShadowsPapa said... my best mileage of 22mpg is around 80km/hr(45-55mph), once I hit highway speeds I drop to around 20mpg, but can go as low as 16mpg if it's windy/hilly.

I have 33" tires. If you have 33" or smaller, I'd be looking into it too, you should do better than 12-14mpg imo.

 

[Sprinkler-Fitter]

I’ve had mine for six months and have never checked the mileage, don’t care.

 

[Lunentucker]

I was really hoping this was going to be someone asking what mpg we were getting in reverse.

 

[Lunentucker]

If your JT looks like mine, I have the same issue.

You need some 37s on that much brick.

 

[Gren71]

Your MPG has a LOT to do with your driving habits.

i get 22-24

2020 sport max tow
255/75/17 Dueler AT

Here is my mpg experiment if your into some reading. May help shed some light on where you can find improvement.
https://www.jeepgladiatorforum.com/forum/threads/mpg-experiment.53810/

 

[Hootbro]

You left out a lot of info. Like what speed are we talking about here? Was it bought used and what model is it and what size tires are on it?

For stock gears and tire sizes, you should be running about 1800-2100 RPM depending on model @ 65 MPH in eight gear.

 

[Jeepasaurus_Rex]

I was really hoping this was going to be someone asking what mpg we were getting in reverse.

Sames. I was severely let down

 

[JustinLentz]

8th gear? What's that like? haha I only see that going downhill on the highway with a gust of wind pushing me along.

You left out a lot of info. Like what speed are we talking about here? Was it bought used and what model is it and what size tires are on it?

For stock gears and tire sizes, you should be running about 1800-2100 RPM depending on model @ 65 MPH in eight gear.

 

[Jeeperjamie]

Anything over 75mph and your going to see a drop in mpg's unless your going downhill. One of the reasons I put a lot of thought in what bumper I put on the front if mine and went with lower profile lights on mine. I've found the sweet spot for hwy driving to be around 60-70 mph. On back roads driving to the beach at speeds between 55 and 60 I can get right at 19 in mine for the roughly 4-1/2 to 4 hour trip.

Sponsored