37s too big for DD?

[guarnibl]

I've been running 37" BFG KO2's for the last 25k miles, 20k of that with no lift, the rest with the Dynatrak 2" lift. 6spd, 4.10 gears. Does fine and somehow did not affect MPG at all (I record every tank). I may swap gears some day, but do not think it is mandatory.

Pete

yep the KO2’s are quite light — possibly why it didn’t really notice much difference. Swap to MT’s, and aftermarket wheels, more lift — and things change quickly.

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[AVGeek99]

The only downside is you're windshield wipers getting bogged down with all the panties women will throw your way lol.

I wont let my wife know about this.

 

[CarbonSteel]

I have 37" Wildpeak AT3W and they run pretty good on the stock 4.10s with my 4 banger, and I run around ski towns in the Rocky's. I have been debating going between 4.88 and 5.13. One shop recommended 5.13 and said they've never done 4.88s. Another shop said that I'd be good with 4.88 with the 2L. I'm still undecided at this point. It's not bad enough to require the upgrade immediately. This is also my DD.

3.6L/ZF8:

33's = 4.56
35's = 4.88
37's = 5.13

2.0T/ZF8:

33's = 4.10
35's = 4.56
37's = 4.88

 

[CarbonSteel]

I'm going into a local shop this week to get on the schedule for a lift (MC Game Changer). I'm trying to decide between a 3.5 inch lift and moving up to 37s or a 2.5 inch lift and sticking with 35s. I know that 37s will require a regear and will go to 4:88s if I go that route. This is for my DD JLUR 6MT. I have about a 40 mile round trip commute each day.

I don't wheel much around home because the options are pretty limited but I do get to Moab once or twice a year and hopefully will be moving out west in the next few years.

I'm really interested in the thoughts of those who have 37s on the DD. Other than having to regear and a potential hit to gas mileage, what are the other negatives of moving up to 37s? If I go to 37s they will be 37x12.5
R17 Cooper STT Pros. I currently have 315/70 R17s STT Pros.

I put 32,000 miles on a set of BFG KO2 LRC 37x12.5x17 as a daily driver. No issues at all--IF it is set up right with suspension and gearing.

I started with 33's with 4.10s
Went to 35's
Then added a 2.5" GC and 4.88s
Then went to 37's (stayed with 4.88s)
Then went to 5.13s
Then added a 3.5" GC.

Without question, the 2.5" GC rides better than the 3.5", but with 37's you will rub with a 2.5" lift.

Everything has a compromise...

 

[Mudduck]

3.6L/ZF8:

33's = 4.56
35's = 4.88
37's = 5.13

2.0T/ZF8:

33's = 4.10
35's = 4.56
37's = 4.88

I see this a lot. What else is taken into consideration when this chart was composed? I regeared from 3.45 to 4.56 while running 285/75/17. Huge difference, and I see 8th at 46MPH. I rarely drop into 7th running 35s now(.5") bigger than the 285/75.

is rig weight, case use, elevation or anything else taken into account? Pretty sure from my RPMs, use and a lot of feedback from others, I could run 37" without issues.

Just curious about the info provided.

 

[CarbonSteel]

I see this a lot. What else is taken into consideration when this chart was composed? I regeared from 3.45 to 4.56 while running 285/75/17. Huge difference, and I see 8th at 46MPH. I rarely drop into 7th running 35s now(.5") bigger than the 285/75.

is rig weight, case use, elevation or anything else taken into account? Pretty sure from my RPMs, use and a lot of feedback from others, I could run 37" without issues.

Just curious about the info provided.

What engine? The 2.0T is more forgiving when undergeared versus the 3.6L. It also depends on your tolerance for this stuff.

I went from 4.88 to 5.13 due to weight and elevation, but in the end, even that was not enough. The 3.6L is a dog above 3K...

 

[Mudduck]

What engine? The 2.0T is more forgiving when undergeared versus the 3.6L. It also depends on your tolerance for this stuff.

I went from 4.88 to 5.13 due to weight and elevation, but in the end, even that was not enough. The 3.6L is a dog above 3K...

I do have the 3.6. looking at the K02s in 37" just under a 6LB difference in the Toyo OC AT3s in 35"

 

[CarbonSteel]

I do have the 3.6

For me, overgearing a 3.6L (if such a thing is even possible LOLOLOL) is more tolerable versus under, but again, it can depend on your tolerance, use case, operating conditions, etc.

 

[Mudduck]

For me, overgearing a 3.6L (if such a thing is even possible LOLOLOL) is more tolerable versus under, but again, it can depend on your tolerance, use case, operating conditions, etc.

Thank you for the reply.

 

[Smoke ‘Em]

2.0 JLR auto. 37” Cooper STT PROs, no gear changes. Had 315 STT PROs on this JLR before the 37s and my previous JLR. Have not regraded, use it as a daily unless it’s a very long road trip. I spend my time between 1300 ft and 9600 ft and have not had any issues with the 37s and would do it again in a heartbeat.

 

[CarbonSteel]

I do have the 3.6. looking at the K02s in 37" just under a 6LB difference in the Toyo OC AT3s in 35"

Many make a big deal out of tire weight and while it should not be dismissed, the diameter and subsequent gear ratio reduction is more important.

 

[AVGeek99]

I have 37" Cooper STT Pros on my 392 XR, and use it as my daily driver. Best driving Jeep I've ever owned. I did not regear.

The STT Pros are awesome tires. I imagine gearing is less of a concern when you have 470hp and lb/ft of torque.

 

[kah.mun.rah]

I'm going into a local shop this week to get on the schedule for a lift (MC Game Changer). I'm trying to decide between a 3.5 inch lift and moving up to 37s or a 2.5 inch lift and sticking with 35s. I know that 37s will require a regear and will go to 4:88s if I go that route. This is for my DD JLUR 6MT. I have about a 40 mile round trip commute each day.

I don't wheel much around home because the options are pretty limited but I do get to Moab once or twice a year and hopefully will be moving out west in the next few years.

I'm really interested in the thoughts of those who have 37s on the DD. Other than having to regear and a potential hit to gas mileage, what are the other negatives of moving up to 37s? If I go to 37s they will be 37x12.5
R17 Cooper STT Pros. I currently have 315/70 R17s STT Pros.

Absolutely go 37s. 35s look too small with a lift and barely a noticeable difference between 35s and 37s as far as performance and mpg.

 

[AVGeek99]

Without question, the 2.5" GC rides better than the 3.5", but with 37's you will rub with a 2.5" lift.

Can you expand on your comment abou the 2.5GC riding better than the 3.5GC. I don't know that I've every seen anyone mention this before. Are you saying the 2.5 rides smoother, or is it more in the handling? Thanks!

 

[c20040215]

Can you expand on your comment abou the 2.5GC riding better than the 3.5GC. I don't know that I've every seen anyone mention this before. Are you saying the 2.5 rides smoother, or is it more in the handling? Thanks!

Probably due to higher spring rate, taller center of gravity, and steeper control arm angle.

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