I was under the assumption that the dura Trac's were a 35" tire. After doing some checking I see they are actually 34.4" Are most tires understated? I have 37/12/17's on my dodge and I guess I never measured them or is it a manufactures thing? I know seems to be splitting hairs and can that .60 be really noticeable??

 

Yes pretty much all tires are understated, that is just manufacturer specs.

If you measure them it will in the 34 range, my BFG ATS are 33.5

 

You can run the calculation yourself to convert to american sizing:

315 is the width in mm
70 is the height of the sidewall as a percentage of the width
And of course 17 is the wheel size

So for this it is:

315mm = 12.4" (this is the width of the tire)
70% of 12.4 = 8.68 (this is the sidewall height)
8.68x2 = 17.36 (sidewall on each side of the wheel)
Wheel size = 17
Total tire size = 17+17.36 = 34.36

 

I see. Crap thats kind of depressing! Not many actually sell the 35x12.5x17 and i did some looking and even they aren't really 35 although closer at 34.8 and 34.9

 

Only women get depressed over half of an inch

 

My BFG 315/70r 17 calculate to 34.4 but measure 33.25 at 33 psi when acutally marked and rotated on a 2007 JK.

 

a 1/2 inch can be the difference between and eww or an AHHHH!

 

That's what she said.


Sorry, somebody had to.

 

Just for the record, I have the 315/70/17 duratracs and they measure 33.5 on the jeep at ~32psi

 

For everyones information I have seen almost every 35" tire available on the market mounted on jeeps courtesy of my buddys garage and not a single one has measured 35" while mounted. Tires measurements should be measured unmounted for true diameter