37's and MPG

[Southbayglad]

So theres a lot of conflicting stuff on here regarding 37's and mpg. Some say they get 18, and Ive read others saying they get 6. So can we have everyone who is running 37's and keeping track, let us know what gears they are running and what their average mpg has been, so we can all get a better understanding of what range we should be in.

-I know this is susceptible to driving conditions, lead foot, modifications, etc etc etc.-

But Id still like to know

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[Ted Striker]

http://www.fuelly.com/car/jeep/gladiator/2020/surebuttercringe/937538

Click on the link above and it will take you to multiple graphs of my Rubicon with 37" Nittos. You'll notice a drop in MPG around August when they were installed - everything before that was stock. Bottom line is that I'm averaging around 15 mpg with just normal every day driving. I'll also add that I have corrected the speedometer calibration with a Tazer JL mini which helped the shift points.

 

[TennesseePA]

I drive so slow on the side streets that I actually get better mileage off of the highway. I get up to 18 if I am on back roads and about 16.5-17 on the highway. Stop and go is about 16 but I use the start stop. I have 37 BFG KO2s so they are only 6 pounds heavier than the stock Falkens. One time for giggles I set my cruise on 65 and drove an hour and 15 minutes to the hospital and was average 19.9 when I got there. But I can’t drive that slow for very long. Usually set the cruise on 75.

 

[Southbayglad]

http://www.fuelly.com/car/jeep/gladiator/2020/surebuttercringe/937538

Click on the link above and it will take you to multiple graphs of my Rubicon with 37" Nittos. You'll notice a drop in MPG around August when they were installed - everything before that was stock. Bottom line is that I'm averaging around 15 mpg with just normal every day driving. I'll also add that I have corrected the speedometer calibration with a Tazer JL mini which helped the shift points.

Very informative as Ill be driving the exact set up as yours as far as wheels.

 

[Southbayglad]

I drive so slow on the side streets that I actually get better mileage off of the highway. I get up to 18 if I am on back roads and about 16.5-17 on the highway. Stop and go is about 16 but I use the start stop. I have 37 BFG KO2s so they are only 6 pounds heavier than the stock Falkens. One time for giggles I set my cruise on 65 and drove an hour and 15 minutes to the hospital and was average 19.9 when I got there. But I can’t drive that slow for very long. Usually set the cruise on 75.

Thats way better than Ive heard. Someone posted a video yesterday saying they were down to "8" I think, before re gearing and I just don't see how thats possible. Im pretty sure Im gonna go with the same tire as you, as the prices are really good as we speak, and will hopefully be better closer to thursday.

 

[Renegade]

I average 15 MPG, but prefer to measure in SPG (smiles per gallon)...it’s a Jeep.

 

[TennesseePA]

I'm not trying to be a smart a$$ or anything but I have been told on many other threads that my Gladiator must be regeared and will not get decent mileage and will never see 8th gear until I add 5.13 to shorter gear. However in reality the Gladiator pulls 8th and 7th gear just fine, even in the hills of Tennessee.

As you can clearly see in the attached photo I'm averaging over 16 mpg on this tank of fuel. Also, to prove my point from other threads, I photoshopped the indicator showing that my Gladiator is cruising on the interstate in 8th gear. We all know that just doesn't happen according to guys who haven't even added tires or a lift to their Gladiator yet. (just kidding I really didn't alter the photo!)

View attachment 48169

View attachment 48172

 

[Southbayglad]

I'm not trying to be a smart a$$ or anything but I have been told on many other threads that my Gladiator must be regeared and will not get decent mileage and will never see 8th gear until I add 5.13 to shorter gear. However in reality the Gladiator pulls 8th and 7th gear just fine, even in the hills of Tennessee.

As you can clearly see in the attached photo I'm averaging over 16 mpg on this tank of fuel. Also, to prove my point from other threads, I photoshopped the indicator showing that my Gladiator is cruising on the interstate in 8th gear. We all know that just doesn't happen according to guys who haven't even added tires or a lift to their Gladiator yet. (just kidding I really didn't alter the photo!)

View attachment 48169

View attachment 48172

I know you probably don't recall but we spoke about it previously lol. I totally agree with you. And I also have buddys who have 37's and are the same opinion as you. I do think it is funny when people who don't even have 37's on yet, have a gladiator for that matter argue with you.

 

[PyrPatriot]

I know you probably don't recall but we spoke about it previously lol. I totally agree with you. And I also have buddys who have 37's and are the same opinion as you. I do think it is funny when people who don't even have 37's on yet, have a gladiator for that matter argue with you.

From another thread

The carrier for 3.73 gears can not take anything bigger so a new carrier is required for 4.10 or higher. If you're going with 37's i would probably be going to 4.56 gears honestly. I have 4.10's in my Sport with 35's and if I went any bigger tires I would go 4.56. My JK has 4.56 and 37's. It is great overall with that ratio.

 

[Southbayglad]

From another thread

I have a jk. It feels like a totally different drive to me than my jt and it isn't eight gears. I have multiple buddies who have 37's who are of the same opinion as teneseepa. So until I get them in December I will have to concede to the experts that do. I just don't see how ppl who aren't running 37's can argue this issue. lol

 

[PyrPatriot]

I have a jk. It feels like a totally different drive to me than my jt and it isn't eight gears. I have multiple buddies who have 37's who are of the same opinion as teneseepa. So until I get them in December I will have to recede to the experts that do. I just don't see how ppl who aren't running 37's can argue this issue. lol

I'll have to argue the issue in a few years when I get 37s and learn more about car mechanics. Until now, I read, and question what I come across by running it past the community of knowledgeable folks here

 

[Southbayglad]

I have a jk. It feels like a totally different drive to me than my jt and it isn't eight gears. I have multiple buddies who have 37's who are of the same opinion as teneseepa. So until I get them in December I will have to recede to the experts that do. I just don't see how ppl who aren't running 37's can argue this issue. lol

I'll have to argue the issue in a few years when I get 37s and learn more about car mechanics. Until now, I read, and question what I come across by running it past the community of knowledgeable folks here

I totally might end up re gearing eventually. But it isn't something Im gonna jump on immediately. I drive in major hills a lot. I climb from 3,000 to 6,000 ft in about 2 hrs to get to our cabin, so it might be an issue for me with towing etc. But I do believe the Gladiator is totally different than the JK, especially with eight speed and 4.10's I have so I don't think it'll be something to stress about. When I get them on, a couple days later well be heading up the hill in snow. So It'll be a good first go at the 37's.

 

[PyrPatriot]

I totally might end up re gearing eventually. But it isn't something Im gonna jump on immediately. I drive in major hills a lot. I climb from 3,000 to 6,000 ft in about 2 hrs to get to our cabin, so it might be an issue for me with towing etc. But I do believe the Gladiator is totally different than the JK, especially with eight speed and 4.10's I have so I don't think it'll be something to stress about. When I get them on, a couple days later well be heading up the hill in snow. So It'll be a good first go at the 37's.

I got the JT for towing/payload. Not for serious offroading. I want the larger tires and lift for the look, but I am function over form if it comes down to it. But I do like functioning tools to look aesthetically pleasing

 

[TennesseePA]

My whole point on the rewearing issue is does any added power at a given driving speed justify the expense and hassle of changing gears. I contend that the horsepower gain is negligible and imperceptible while driving since the rpm change is so small. If you change from a 4.10 to a 4.56 you will only get a 9 % rpm change. For rounding purposes lets use 10% and assume that the Gladiator makes it's maximum torque at 2000 and 2500 rpm (260*2250/5252=111HP)-(260*2000/5252=99HP). In the grand scheme of driving on regular roads at highway speeds I do not see where the additional 12HP will make a noticeable difference. And as we all know the 3.6 pentasutar doesn't make anywhere near it's peak torque at 2000-2500 RPM range, so with that in mind the actual difference is even less than the math above shows.

 

[a.k.a. Bruni]

i just bought a 2020 Gladiator with Nitto 37's this week and i drove for 4 hours and my MPG was 10mpg. What do I need to look for or do to get the 16mpg or higher? Thanks, Mike

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