HELP with tire sizes

S

Stephane87

New member
Hi, I’m need help with tires sizes.

I have a JKU Sahara 2017 with stock wheels (18”), 255/70R18 (31.5” or 32”), no lift, automatic, 3.21 gears, stock coil springs (17/57). This is my 3rd jeep (1987,2010,2017) and I don’t want to go over board like I did in the past. Also, It’s my DD and will do minimal off road like country roads (no rock).

My goal is to have nice tire size with a 2”-2.5” lift maximum. I was thinking of AEV 2” spacer lift with Toyo Open Country AT2 (LT or Xtreme) in 33” or 34” tires. I found a tire size calculator (tacomaworld.com) that I used to compare and convert different sizes in inches. I was interested in those 3 sizes:

275/70R18 = 33.1”
295/70R18 = 34.2”
285/75R18 = 34.8”

Today I saw some comments from Eddie about tires and I got confused. He was talking about 34” really being 33”, some 37” really being about 35”, 33” more like 32”....so that’s why I need help. AEV told me I can put max 34” with there 2” spacer lift...but what size would be a real 34”? I also have a Daystar 1.75” spacer lift in a box in my garage (4 x 1.75”)...so can I go up to 34” tires with that kit? And last, is 34” going to kill my 3.21 gears (I’m in Canada, flat city)?

Thanks a lot

Stephane
 
Last edited:
Honor2afault

Honor2afault

Caught the Bug
I believe that what Eddie was referring to is that not all tires are made to the same dimensions, regardless of how they're designated for size. Also, that after you have them mounted and put on the jeep the actual measurements will be different.
As for the difference it will make with 3.21 gears is that you speedometer will be off a bit. This, of course, is easily alleviated with any of several aftermarket programmers. Many of which are quite affordable.

Courtesy is given. Respect is Earned.
 
WJCO

WJCO

Meme King
Let's use a 35 inch tire for example. Even with it off of the Jeep and brand new, it won't measure 35 inches. It will likely be a low 34. Then when you air it up, and install it, the weight of the jeep will cause the diameter to be even less. You could probably run a tall 33 inch tire and trim your fenders and you wouldn't even have to lift the jeep. Check out our true tire size thread:

https://wayalife.com/showthread.php/35075-The-Ultimate-TRUE-TIRE-SIZE-Database
 
2nd.gunman

2nd.gunman

Caught the Bug
Also it's worth noting that if a particular lift is designed to fit up to a certain tyre size they mean advertised size not actual size as that changes slightly from brand to brand.


Sent from my iPhone using WAYALIFE mobile app
 
S

Stephane87

New member
Ok so if my lift says maximum 34” tires, do I buy a tire that says 34” on the side or one that’s about 1.5” taller (then my he side specs) like 35”-35.5” knowing that in reality it will be smaller?
 
wayoflife

wayoflife

Administrator
Staff member
Stephane87 said:
Ok so if my lift says maximum 34” tires, do I buy a tire that says 34” on the side or one that’s about 1.5” taller (then my he side specs) like 35”-35.5” knowing that in reality it will be smaller?
Click to expand...

You want to get what's stated on the sidewall. Yes, it'll be SMALLER than 34" but it'll be correct for your lift.
 
WJCO

WJCO

Meme King
Stephane87 said:
Ok so if my lift says maximum 34” tires, do I buy a tire that says 34” on the side or one that’s about 1.5” taller (then my he side specs) like 35”-35.5” knowing that in reality it will be smaller?
Click to expand...

How high is your current lift?
 
S

Stephane87

New member
Question for Eddie; would you go for AEV 2” spacer lift with 34” or Daystar 1.75” all around spacer lift with 34”?
 
wayoflife

wayoflife

Administrator
Staff member
Stephane87 said:
Ok. Do 1.75” all around give enough space for 34” tires?
Click to expand...

What I can tell you is that MOST 2" spacer lifts have a true measurement of 1.75". Typically, this will get you clearing an advertised (on the sidewall) 35" tire with maybe some minor rubbing. 34" should be fine. I don't know about the AEV spacers but even IF they are a true 2", I doubt the extra .25" will make much of a difference.
 
S

Stephane87

New member
Ok so make sens to me. Knowing that the AEV real 2” front and 1.5” rear then I’m good with 34” tires. So the Daystar 1.75” all around (i measured them and it’s really 1.75” all around) would also clear 34” (sidewall) if I add bumpstop, brake Line extensions...
 
You must log in or register to reply here.
Top Bottom