245 or 285 tires?

The 245 = 9.6 in
The 285 = 11.2 in

How much backspacing do you have on those 16's?

Get C load tires.
 
The 245/75R16 will be a 30.5 tire.
The 285/75R16 will be 32.8.

Maybe this will be helpful:

Let's use 285/70R17 as an example.

285 is the section width. It's the width of the tire in millimeters.
70 is the aspect ratio. It indicates the height of the sidewall in relation to the section width. An aspect ratio of 70 means that the sidewall's height is 70% of the section width.
17 is the rim diameter in inches. The R simply means that the tire is a radial tire, which is what you want.


So, to find the overall diameter of a tire we have to do a little converting.

Overall Diameter = [(Section Width/25.4) x .Aspect Ratio x 2] + Rim Diameter

First, you convert the section width to inches by dividing by 25.4, because there are exactly 25.4 millimeters in 1 inch.
285 / 25.4 = 11.22 in.

So, the tire is 11.22 inches wide. Now we multiply by the aspect ratio to find how tall the sidewalls are.
11.22 x .70 = 7.85 in.

Since we have two sidewalls, we have to multiply by 2.
7.85 x 2 = 15.7 in.

Then add the diameter of the rim.
15.7 + 17 = 32.7 in.

So the overall diameter of a 285/70R17 tire is approximately 32.7 inches (without the weight of the vehicle sitting on it).

Copied and pasted from another source
 
  • Like
Reactions: Michael2006 and JMT
This site contains affiliate links for which Jeep Wrangler TJ Forum may be compensated.
For Backspacing, measure from the back edge of the rim to the center of the rim. Less BS (3.75-4" is ideal) means your rim will stick out further giving you more room in the fender well for a wider tire. If you have a 1" spacer, that will help if you have a larger BS, like 5-5.5".

IMG_5827.GIF
 
  • Like
Reactions: Octavio Lizarraga
Michael2006 said:
@JMT So it's width. Not sure about the backspacing. Will definitely check out how to measure that. I have wheel spacers, I think one inch.
Click to expand...

Correct. The way to read Metric tire sizes is Width(in mm) / sidewall (as a percentage of width) RXX (wheel size in inches).

For your 285/75R16, for example:
To get width divide the first number by 25.4 so 285/25.4 = ~11.2"
Sidewall size = 11.2*.75 = 8.4"
For overall tire diameter multiply this x2 and add in your wheel size = 8.4*2+16 = ~32.8"
i.e. 32.8x11.2R16 if converted to imperial units.

245/75R16 = 30.5x9.6R16
 
With a two inch lift, you'll be pretty tight on clearance with those 285's. It can be done, I have a buddy that wheels with 33's and a two inch lift but he has some rubbing issues as well. Might try a 265 style tire.
 
  • Like
Reactions: JMT
You should also consider gearing. That difference in tire diameter is going to be noticeable, and not in a good way.
 
Agreed, stay away from that 285 tire which is too tall for your 2" of lift. Also, it'd be a good idea to avoid Load Range D or E tires, they are meant for much heavier vehicles and are too stiff for a Wrangler. I mean they are usable, but a Load Range C is optimal. Not to mention D and E LR tires are less flexible so they would not have as good of offroad traction at the same air pressure as a LR C tire would.
 
  • Like
Reactions: Michael2006
I have 285 75 R16's on the factory wheels. The fit is tight, and there is some rubbing at lock out. I knew that going in. It don't go anywhere that flex is an issue. Gearing is fine with the Rubi, performance degrading is mild. Any higher gear though, and it would be an issue. Keep in mind function. For me, the soft sand of the beaches is as intense as the off-road gets. This set up would not work well for anything much more adventurous.
 
Top Bottom
Back