In 2015, the standard model was the 225 w/steel wheels, the Sport S option which I believe was $2500 more (I ordered my Jeep so I picked exactly what I wanted). The S package was AC & the bigger tires you mention plus I believe some other misc trim. At the time, I didn't care about the tires/wheels so I ordered the AC for around $1k.
Anyway, I just bought the 17" wheel/255's off another member who upgraded his tires.
The picture below is the 255's in the the front & the stock 225's in the back before I finished changing them all. Jeep's now about 1-1/2" to 2 inches taller.
Let's suppose that all you're going to do to the wrangler is add a boost using ungraded Mopar coils. (which is what we're hoping to do ourselves) But keeping the 225/75/16'a on this lift would cause a stability issues as you've suggested. I personally don't feel the 225's are meant to be abused in this manor. small tire basic wheels/rim on a lifted wrangler would have a funny appearance and be unsafe. yet I have seen others running around town with this set up, I think caution would need to be used in this instance.
Then let's take this a bit farther.. suppose you add a few accessories, nerf bar, heavier bumpers ete. Even though the 225's have a load rating.. adding all this other stuff is going to stress the tires and give you a very flat performance feeling, sluggish and could be all over the road. At which point you should at least upgrade as @CJ River Rider did with his jeep by adding the 17'' 255 and nothing would need to be changed, unless you wanted to change the coils/shocks. The 255's would offer more stability and a wider stance.
Here's a shot of my stock LT255/75R17C tires on my Willys with an AEV 2" Spacer Suspension Lift. I'm planning on switching to 33s when the stocks wear out or Duratracs go on sale, whichever comes first. I really like the wheels. The tires, not so much.
Something to consider, if the Jeep comes with the 225 75 16 it most likely have the 3.21 gears. If it came with 255 75 17 it most likely have the 3.73 gears.
If it has 3.21 you will not want to run tires much larger than stock.
Just wanted to say something here, when I say "lift" I'm merely suggesting that when one remains with stock coil and shock options you would gain a slight boost. So no official lift is in our books.. But a simple coil upgrade might be a better option for you down the road. The stock 2 & 4 door wranglers come with a "normal duty suspension" Jeep offers a heavy duty and the performance suspension as options on several wrangler.. But if you're going to actually lift the wrangler, Mopar has the 2'' & 4'' inches lift kits.
In other words, know your coils tags number before you decide what to do next. We test drove a wrangler unlimited over the weekend. At which time, I had a chance to examine the coils. This particular unlimited sport has 17 front and 58 rear. (normal duty) I could increase this with the heavy duty or performance. Often this just means upgrading the shocks. But I wanted that boost, so we may opt for the 19/60 set up as installed on most Rubicons etc.
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