Lift or not, the JGC's effective maximum tire diameter is ~32". The edge-of-tread design matters when you get up to the limits, too. If you upsize your tires, you must also upsize your spare to match if you have 4x4. Your speedo and odo will no longer be accurate and there's no inexpensive or easy way to adjust for that. There are so many threads here on this topic...enjoy them.

BTW, since you have a High Altitude, according to your user name, there is no lift you can add...you have the air suspension which is variable height already, at least at slow speeds.

 

The tire size, correct with stock suspension. I could lift it, I would just be foregoing the current air suspension and probably voiding the warranty- which I don't want to do. Yes, I'd need to have the odometer and speedo corrected for a change in tires.

The main question was the offset number in wheels to allow a 31 or 32 tire (not 33 like previously stated). i think a +20 may be the most aggressive offset that will work without a lift or fender rubbing, but maybe that's too much. Would it be +25, +30??? Any personal experience in this without a lift or fender rub. Tires just past the shoulders of the vehicle. If there is any rubbing, anyone have experience in fender trimming without it looking chewed up?

 

Swapping out QL for a spring suspension is doable....Rocky Road is about to release their kit...but it's expensive and you have to live with the computer errors. And yes, your warranty relative to anything about the suspension and related things would likely be toast.

As to spacers...some tires will not need them; some might...there are many threads here that detail tire choices and setups. And with QL, you also have to remember that it doesn't just go up, it also goes down for Aero mode at higher speeds and even lower for park mode, if you happen to use it.