Tire size differences

BigClay

Knower of useless ZJ things
Joined
Sep 24, 2008
Location
Winston-Salem
So I currently have 33x12.5 bias TSLs on my TJ. I have been tossing around the idea of getting a used set of tires to run on the road and keep the TSLs for the trail. Looked at Interco's website and my current tires measure 33.7" by 12.4" and weigh 62 pounds. I checked the specs on a BFG AT and their 35x12.5 tire measures 34.7" by 12.7" and weighs 55 pounds.

So by going to a 35x12.5 BFG tire I will save 7 pounds a tire and really only get a 1" taller tire.

Why such the differences in actual vs stated sizes between manufacturers?
 
Didn't think about that, so I just checked the radial TSLs and you are right a 33 measures 32.7, an inch smaller than the bias
 
Most tires measure smaller than their stated size. A few of the Swamper sizes measure larger for some reason.
 
I THINK it is because the bias ply crosses over each ply making it a little taller, don't know for sure just a guess!
 
BFG is notoriously small, except when it comes to sticky krawlers. A 35x12.50 km2 is really a 32" in other tires standards.
 
BFG is notoriously small, except when it comes to sticky krawlers. A 35x12.50 km2 is really a 32" in other tires standards.

Interesting! !!! I just took of km2 35's and am getting the tera graple 35's I thought the kms looked small on my truck! So the nitto may look a little bigger!!??
 
Should.
 
There is no logical relation in tire sizes, you'll only hurt your brain trying to figure it out. 33 TSLs have always been huge. 36 Iroks too. Tires are made in a mold that is accurate to within a couple thousandths of an inch, so I don't know why they don't make them actual size.
 
I was told that some tires that were being designed as off road tires, the tire company went and figured out what tire pressure most people were running then made them to be true 36" at say 5psi so filled up to 35 psi they are bigger than labeled
 
I was told that some tires that were being designed as off road tires, the tire company went and figured out what tire pressure most people were running then made them to be true 36" at say 5psi so filled up to 35 psi they are bigger than labeled
Trust me, there is no logic here. 36" bias ply Iroks are taller than 37" bias ply Iroks.
 
My new 40/16-17 ltb jack stands measure 37.5x 14 on 8" wheels with 3 psi.
 
Here are the pictures: 33" bias TSL and 35" BFG AT

ImageUploadedByTapatalk1433600630.919448.jpg


ImageUploadedByTapatalk1433600643.716673.jpg
 
My new 40/16-17 ltb jack stands measure 37.5x 14 on 8" wheels with 3 psi.

I'm thinking about running a set of those on my k5.... Wondering the 39" iroks are taller....
 
If the 39 iroks had as much tread as the 42 iroks it would be a great tire. It's been a long time since anyone I know had 39 iroks I can't remember what they measured. The 40 ltb has MUCH more meaty treads than the 39 irok and was a lot cheaper. My $0.02
I'm thinking about running a set of those on my k5.... Wondering the 39" iroks are taller....
 
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