Anybody running 37’s with 5.13s?

[SwampRat91]

I am wondering if anybody in here is running 5.13s with 37s. The question I have is how is it on the highway when doing 70ish. What’s your fuel mileage like in town and cruising the highway? Right now for work I drive mostly city but may be taking a job where I’ll be mostly driving interstate. I also tow a 20’ bay boat down the interstate at times so I know 5.13s was probably my best option but wondering what they are like on the interstate rpm and mpg wise?

thanks

Sponsored

 

[JT1]

I am wondering if anybody in here is running 5.13s with 37s. The question I have is how is it on the highway when doing 70ish. What’s your fuel mileage like in town and cruising the highway? Right now for work I drive mostly city but may be taking a job where I’ll be mostly driving interstate. I also tow a 20’ bay boat down the interstate at times so I know 5.13s was probably my best option but wondering what they are like on the interstate rpm and mpg wise?

thanks

I am going to assume 8spd since you didn't specify, and because the boat and trailer are probably right at the 4500 pound max of the manual. 70ish you'll be running a touch over 2100rpm (36.5" tire) in 8th, and still under the second stage oil pump in 7th..

 

[SwampRat91]

I am going to assume 8spd since you didn't specify, and because the boat and trailer are probably right at the 4500 pound max of the manual. 70ish you'll be running a touch over 2100rpm (36.5" tire) in 8th, and still under the second stage oil pump in 7th..

Yea my bad, that’s kind of a key part not to leave out lol… 8 speed 2022 gladiator altitude

 

[JT1]

Yea my bad, that’s kind of a key part not to leave out lol… 8 speed 2022 gladiator altitude

Tire size (BFG I'm looking at you) varies a lot on 37's. Some are in the mid 36"s, the KO2s are about 35.5" and will have a small effect on cruising RPM.

 

[SwampRat91]

Tire size (BFG I'm looking at you) varies a lot on 37's. Some are in the mid 36"s, the KO2s are about 35.5" and will have a small effect on cruising RPM.

I’m gonna be running iron man’s all country mt’s… not a fan of cheaper tires but had a buddy get 45k out of them on a ram 3500 so I figured I’d give them a shot

 

[JT1]

I’m gonna be running iron man’s all country mt’s… not a fan of cheaper tires but had a buddy get 45k out of them on a ram 3500 so I figured I’d give them a shot

With the auto 4.88s or 5.13s are fine. At sea level in LA you can probably get away with either.

 

[SwampRat91]

With the auto 4.88s or 5.13s are fine. At sea level in LA you can probably get away with either.

Thanks for info… you know what the fuel mileage would be like with 5.13s? I know I know it’s a lifted jeep you shouldn’t be worried about fuel mileage but I’m just curious lol

 

[JT1]

Thanks for info… you know what the fuel mileage would be like with 5.13s? I know I know it’s a lifted jeep you shouldn’t be worried about fuel mileage but I’m just curious lol

Mine is a manual, so not apples to apples. With 3.73s and 37s, I averaged about 14, after the 5.13s it averages about 15.5 in mixed driving. Highways out here are 70 or 75 though. At 65 I can squeek 19-20.

 

[SwampRat91]

Mine is a manual, so not apples to apples. With 3.73s and 37s, I averaged about 14, after the 5.13s it averages about 15.5 in mixed driving. Highways out here are 70 or 75 though. At 65 I can squeek 19-20.

Not bad at all, would the auto get better or worse you think? I’m loss when it comes to regearing and am new to the jeep world too lol… me and my wife both sold our vehicles and went bought jeeps.. I had a brand new Duramax I traded in so everything is just different lol

 

[JT1]

Not bad at all, would the auto get better or worse you think? I’m loss when it comes to regearing and am new to the jeep world too lol… me and my wife both sold our vehicles and went bought jeeps.. I had a brand new Duramax I traded in so everything is just different lol

Honestly no idea. I'm sure one of those guys will hop on here soon.

Mine when it still had 3.73s was essentially a 4 speed, 5th and 6th didn't have enough rpm to pull a decent hill at 75 without a downshift, and because you were flat to the floor, mileage tanked. Now I can put it in 6th and set the cruise and it just does it's thing, much less drama.

Around town its a ton more fun. 2nd and 3rd gear are entertaining.

 

[SwampRat91]

Honestly no idea. I'm sure one of those guys will hop on here soon.

Mine when it still had 3.73s was essentially a 4 speed, 5th and 6th didn't have enough rpm to pull a decent hill at 75 without a downshift, and because you were flat to the floor, mileage tanked. Now I can put it in 6th and set the cruise and it just does it's thing, much less drama.

Around town its a ton more fun. 2nd and 3rd gear are entertaining.

I’ll post some pics of the build when I’m done!!

 

[Dlish]

37's and 5.13 are perfect imho.

If out west and running 85+mph all the time, maybe not as you would be in the second stage of the oil pump. but for under 80 its awesome to be in 8th gear and not downshift all the time.

If your highway speed is closer to 70-75 and in-town driving, the combo is great from a driving perspective. I dont track my milage, its a brick and it is what it is. I drive to get somewhere as well, the auto-stop is turned off with a Tazer, and I absolutely never drive thinking about how I could get better mpg. that said, just looked and seems to be around 14. My daily commute is 12 miles and lots of stop signs and lights. No highway.

 

[SwampRat91]

37's and 5.13 are perfect imho.

If out west and running 85+mph all the time, maybe not as you would be in the second stage of the oil pump. but for under 80 its awesome to be in 8th gear and not downshift all the time.

If your highway speed is closer to 70-75 and in-town driving, the combo is great from a driving perspective. I dont track my milage, its a brick and it is what it is. I drive to get somewhere as well, the auto-stop is turned off with a Tazer, and I absolutely never drive thinking about how I could get better mpg. that said, just looked and seems to be around 14. My daily commute is 12 miles and lots of stop signs and lights. No highway.

Still not terrible for a 6 cylinder on 37s

 

[Lumis]

I'm going 4.88, 8 speed auto. My son did 4.88 with 37's, 8 speed auto, in Provo UT, works great. Highway speeds are harder on gearing and lube oil the further you go on gearing. For me it's my DD so, 4.88's. Plus, since you can now do mopar 4.88, you save your warranty. To each there own I guess

 

[Bbannongmu]

I am wondering if anybody in here is running 5.13s with 37s. The question I have is how is it on the highway when doing 70ish. What’s your fuel mileage like in town and cruising the highway? Right now for work I drive mostly city but may be taking a job where I’ll be mostly driving interstate. I also tow a 20’ bay boat down the interstate at times so I know 5.13s was probably my best option but wondering what they are like on the interstate rpm and mpg wise?

thanks

Really depends on where you are driving and what your needs are. I have 37x12.50 Mickey Thompson Baja AtzP3 and Yukon 5.13 gears and manual transmission . I just did a 5,600 road trip to Yellowstone and back from PA. I chronicled my mpgs on my YouTube channel. https://youtube.com/c/JTRSpartacus never great but better than expected. Even with 5.13 gears I often had to downshift from 6th gear to 5th (and sometimes 4th gear)to get up interstate grades. Of course auto trans will be a bit different. YMMV. Good luck

Sponsored