Originally Posted by joemaxtravbran
When the tires finally wear out I was thinking of going to 285/70/17. Well I just figured out in english what size that is compaired to the 255. 255=32" approx. & 285=35" approx. Now I am wondering about the weight difference? 255/75/17 w/rim approx 80lbs? What would a 285/70/17 +/rim weight? & would that weight be to much for the rear gate? I am not wanting to replace the rear bumper @ this time. TIA
Whoa there. You're a bit off.
There are many threads which will help you figure out what the numbers mean, and how large of a tire you can fit:
I'm lost on wheels and tires
Largest tire on stock JK? Here's your answer!
Tire Dimensions Made Simple - Discount Tire
But here's the skinny just to get you more on the right track:
The 255 refers to the width, which in your case does equate to a 32" tire. However if you ran a 255/50R17, that would NOT be a 32" tire, even though it's still a 255.
First number (255) = tire width in millimeters
Second number (75) = percentage of that width for the sidewall height
Third number (17) = diameter of the opening for the wheel
A 275/70R17 is also a 32" tire. It's just wider and the sidewall percentage is smaller. This mathematically works out to a tire which is wider, but has the same sidewall height as the 255/75R17.
So, so if you wish to run a 285/70/17 (which MANY do), you're essentially going up to a 33" not a 35" tire.
285 x 70 = 199.5mm (one sidewall height)
199.5 x 2 = 399 mm (two sidewall heights)
399mm = 15.7087" (total sidewall in inches)
15.7087 + 17 = 32.7087 (total tire/wheel height)
As far as the weight goes, I think the 285 with stock Rubicon wheel will work fine on your tailgate, but you might want to consider different bumpstops to ensure the wheel stays tight against the carrier.
Be sure to read the threads linked above and ask more questions, but at the end of the day, a 285/70/17 is a fine tire to run on stock wheels with stock suspension (for the most part). That 285 will rub slightly when turning and/or flexing. That will also be covered in the other threads.