Hard data on 37s

At Risk Ute · Dec 14, 2023

Fast-n-Furious said:
Looking great! Did you test drive with 37” before adjusting tire size? Wondering how big a difference.

Adjusting the tire size with the Tazer? I did not.

Viking Jeeper · Dec 14, 2023

At Risk Ute said:
Adjusting the tire size with the Tazer? I did not.

From a percentage change perspective there really is not much change from 35-37.

Fast-n-Furious · Dec 14, 2023

At Risk Ute said:
Adjusting the tire size with the Tazer? I did not.

Man that’s great to hear! I don’t want a Tazer and I’ve heard lots feedback say you need to adjust the tire size to correct the speedo and gps when going to 37 from 35.

JDP392 · Dec 14, 2023

2024 Rub 392 stock suspension. I went with the 18” KO2, which are 37x13.5x18. I wanted the extra width. Tread width on 315s is 10.6, on the 17x12.5 it’s 10.1, and on the 37x13.5x18 it’s 11.1. I previously tried the 37x12.5 x17. No rubbing with the 13.5 on all pavement driving. We all know if wheeling, you need some mods. 0-60 on 315s was 4.1, with 37x12.5x17 just under 4.5. Haven’t clocked the 13.5s (heavier) but I can tell there’s a bit of a difference.

JDP392 · Dec 14, 2023

Btw, tires are E load range and psi is at 36.

Tank2112 · Dec 14, 2023

JDP392 said:
View attachment 29056 View attachment 29057 View attachment 29058 View attachment 29059
2024 Rub 392 stock suspension. I went with the 18” KO2, which are 37x13.5x18. I wanted the extra width. Tread width on 315s is 10.6, on the 17x12.5 it’s 10.1, and on the 37x13.5x18 it’s 11.1. I previously tried the 37x12.5 x17. No rubbing with the 13.5 on all pavement driving. We all know if wheeling, you need some mods. 0-60 on 315s was 4.1, with 37x12.5x17 just under 4.5. Haven’t clocked the 13.5s (heavier) but I can tell there’s a bit of a difference.

Looks good. Thinking about doing same thing. However, to me looks like a 1" coil spacer would add the right amount of lift for 37" tires. And I'm not one for a lot of space between tire and fender.

At Risk Ute · Dec 15, 2023

Fast-n-Furious said:
Man that’s great to hear! I don’t want a Tazer and I’ve heard lots feedback say you need to adjust the tire size to correct the speedo and gps when going to 37 from 35.

My apologies. Santa’s little elves tazed them to the correct tire size.

For me, a tazer is worth it just to read codes and kill nanny shit like the seat belt chime and keys out honk. For the 392, I love having push button 2H. Steering is much lighter at low speeds.

redrubi · Dec 15, 2023

Viking Jeeper said:
BF Goodrich says the 37 inch tires are exactly 2 inches bigger than the 315/70-17.

THAT``S FUNNY!!

4x4ready · Dec 15, 2023

redrubi said:
THAT``S FUNNY!!

The 315s I had were more narrow then my 37s. 37s being taller of course

redrubi · Dec 15, 2023

4x4ready said:
The 315s I had were more narrow then my 37s. 37s being taller of course

I have 37x12.50x17 on Xtreme 25 bolt beadlock wheels and if you run a measuring tape around the spare it comes out to be 113" with 35 psi in it and when you do the math they turn out to be 35.99 and they are even less once mounted on the Jeep with 33 / 35 psi in them
If you go on BFG`S site and look at the 315x70x17 the width is 12.7 on a 9.5" rim The 315" and the 35" both measure 34.4 tall
When you check the 35x12.50x17 the width is 12.5 on a 10" rim
The 37" is basically the same as a 35"
The 37" measures 36.5" on the site

Shop All Terrain T/A KO2 Tires | BFGoodrich Tires

Buy BFGoodrich All Terrain T/A KO2 tires for BFG's toughest all terrain tire ever. Enjoy tougher sidewalls and aggressive traction, even in the winter.

www.bfgoodrichtires.com

JDP392 · Dec 15, 2023

At Risk Ute said:
My apologies. Santa’s little elves tazed them to the correct tire size.

For me, a tazer is worth it just to read codes and kill nanny shit like the seat belt chime and keys out honk. For the 392, I love having push button 2H. Steering is much lighter at low speeds.

where did you find your tazer?

JDP392 · Dec 15, 2023

redrubi said:
THAT``S FUNNY!!

I didn’t see it on the 37x12.5x17, mounted though. Maybe without the weight of the vehicle. My 37x13.5x18 at 38 psa are just about 36”

JDP392 · Dec 15, 2023

4x4ready said:
The 315s I had were more narrow then my 37s. 37s being taller of course

KO2s??

At Risk Ute · Dec 16, 2023

JDP392 said:
where did you find your tazer?

I previously bought it from Santa’s workshop when I completed my pavement Princess build. Was always there. Misunderstood your original question.

4x4ready · Dec 19, 2023

JDP392 said:
KO2s??

Yes, the original 315s were KO2s and the contact patch of the tire are about an inch wider then the 37x12.5 R17 KO2s I replaced them with. I weighed both on a scale when in installed the Nomad split spokes w/ 37s and came out 3-4 lbs lighter per wheel. Was just saying maybe makes sense since the 37s are more narrow

JDP392 · Dec 19, 2023

4x4ready said:
Yes, the original 315s were KO2s and the contact patch of the tire are about an inch less in width then the 37x12.5 R17 KO2s I replaced them with. I weighed both on a scale when in installed the Nomad split spokes w/ 37s and came out 3-4 lbs lighter per wheel. Was just saying maybe makes sense since the 37s are more narrow

That’s the opposite of my experience on the contact patch and tread width.

4x4ready · Dec 19, 2023

JDP392 said:
That’s the opposite of my experience on the contact patch and tread width.

Brain fart, I misspoke. The 315s are wider then my 37x12.5R17s.

JDP392 · Dec 19, 2023

4x4ready said:
Brain fart, I misspoke. The 315s are wider than my 37x12.5R17

4x4ready said:
Brain fart, I misspoke. The 315s are wider then my 37x12.5R17s.

Ok. Now we’re on the same page. I love the look and feel of the 37x13.5x18s that I replaced them with. The width is perfect for my liking. But I’m not wheeling anymore so it’s really just aesthetics and dry and wet traction.

redrubi · Dec 19, 2023

These are 37x12.50x17 Nitto Ridge Grapplers on a 2021 392XR no lift, that will change soon. Rims are Raceline Defender 17x9 4.5” b/s -12mm offset

This setup with TPMS weighs in at 110 pounds

The stock 25 bolt XR wheel with a BFG KO2 37x12.50x17
C rating TPMS, weighs in at 104 pounds

Fast-n-Furious · Dec 19, 2023

redrubi said:
These are 37x12.50x17 Nitto Ridge Grapplers on a 2021 392XR no lift, that will change soon. Rims are Raceline Defender 17x9 4.5” b/s -12mm offset

This setup with TPMS weighs in at 110 pounds

The stock 25 bolt XR wheel with a BFG KO2 37x12.50x17
C rating TPMS, weighs in at 104 pounds

Sharp looking! Great data points for comparison!