37x12.5 vs 38x13.5
Thread Starter
JK Enthusiast
Joined: Jul 2011
Posts: 125
Likes: 0
From: Northern Illinois
37x12.5 vs 38x13.5
Hey JKF,
Im looking to step up from 35s soon and was wondering, will 38s be that much worse than 37s for my D30? I now its all dependent on how I wheel and tons of factors, but Im looking at yokohama geolander mts and the 38x13.5x17s are only 5 lbs heavier than the 37x12.5x17s and the 38s are a bit cheaper. if they offered a 37 in a 13.5 I'd spring for that cause I want the extra width but they dont. I plan to build up the D30 and I only wheel in mud here in IL. I know 37s on a D30 is a bad idea, but would 38s be that much worse of an idea? Thanks
Im looking to step up from 35s soon and was wondering, will 38s be that much worse than 37s for my D30? I now its all dependent on how I wheel and tons of factors, but Im looking at yokohama geolander mts and the 38x13.5x17s are only 5 lbs heavier than the 37x12.5x17s and the 38s are a bit cheaper. if they offered a 37 in a 13.5 I'd spring for that cause I want the extra width but they dont. I plan to build up the D30 and I only wheel in mud here in IL. I know 37s on a D30 is a bad idea, but would 38s be that much worse of an idea? Thanks
Former Vendor
Joined: Apr 2013
Posts: 740
Likes: 1
From: Colorado
I highly doubt that they are truly only 5 pounds heavier.
The extra width adds a larger contact patch which puts more strain on your drivetrain. Personally, the 38s are closer to a 40 than a 37 in my mind. Also this will be said alot but you are definitely pushing the limits of a D30 if you are wheeling...
The extra width adds a larger contact patch which puts more strain on your drivetrain. Personally, the 38s are closer to a 40 than a 37 in my mind. Also this will be said alot but you are definitely pushing the limits of a D30 if you are wheeling...
JK Super Freak
Joined: Apr 2007
Posts: 1,258
Likes: 1
From: Prosper, TX
Dang. Why did I have to look at this thread. Now I'm going to be wanting a set of these 38s!
$333 a tire?!!!!
Okay, I feel better now. Many reviews show weak sidewalls and that won't work for me. The rocks here are not forgiving and I really hate having to change tires on the trail due to a ripped sidewall.
$333 a tire?!!!!
Okay, I feel better now. Many reviews show weak sidewalls and that won't work for me. The rocks here are not forgiving and I really hate having to change tires on the trail due to a ripped sidewall.
Last edited by CJ7nvrstk; May 14, 2015 at 03:48 AM. Reason: Read reviews of this tire.
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Former Vendor
Joined: Jan 2015
Posts: 289
Likes: 0
From: Jacksonville, FL
I ran the Geolander MT+ in a 38 on one of my '07's. Great tire. My only complaint is that they always seem to be on back order when ever I'm looking for a new set of rubber, otherwise I would still be running them.
Michael @ Level 10
Michael @ Level 10
JK Junkie
Joined: Jun 2013
Posts: 3,697
Likes: 2
From: Grosse Pointe, MI
Personally, I have to agree with this. Not to mention that this post provides the most technical insight of any post in this thread.
That said, if you can clear the 38s, you can pretty much clear 40s. I'd strongly consider a light 40 like the MTR. As for the D30, I'd recommend not running any gussets or sleeving/trussing the axle. With the larger tires like that, it helps by allowing the axle and C's to flex and absorb the forces. The JK axle should run fine with camber up to around a -10 degrees. Even beyond that is fine, it just might cause slightly accelerated tire wear.
That said, if you can clear the 38s, you can pretty much clear 40s. I'd strongly consider a light 40 like the MTR. As for the D30, I'd recommend not running any gussets or sleeving/trussing the axle. With the larger tires like that, it helps by allowing the axle and C's to flex and absorb the forces. The JK axle should run fine with camber up to around a -10 degrees. Even beyond that is fine, it just might cause slightly accelerated tire wear.
JK Super Freak
Joined: Apr 2007
Posts: 1,258
Likes: 1
From: Prosper, TX
Personally, I have to agree with this. Not to mention that this post provides the most technical insight of any post in this thread.
That said, if you can clear the 38s, you can pretty much clear 40s. I'd strongly consider a light 40 like the MTR. As for the D30, I'd recommend not running any gussets or sleeving/trussing the axle. With the larger tires like that, it helps by allowing the axle and C's to flex and absorb the forces. The JK axle should run fine with camber up to around a -10 degrees. Even beyond that is fine, it just might cause slightly accelerated tire wear.
That said, if you can clear the 38s, you can pretty much clear 40s. I'd strongly consider a light 40 like the MTR. As for the D30, I'd recommend not running any gussets or sleeving/trussing the axle. With the larger tires like that, it helps by allowing the axle and C's to flex and absorb the forces. The JK axle should run fine with camber up to around a -10 degrees. Even beyond that is fine, it just might cause slightly accelerated tire wear.